Database Users

[Q] Need help with discount calculator

I am a newbie in android dev.
I want to develop a very small and simple discount rate calculator.
in which there will be drop down menu with options like:
calculate 10%
calculate 20%
calculate 30%
Based on the selection of option from the drop down menu the discount rate should change.
After selection, there will be a textbox which should ask user to enter price.
and on the click even of "Calculate" button, the resultant amount (discounted rate) should be displayed.
I guess it is very simple for you guys. If anyone can help me with the code, i will deeply appreciate.
thank you

ok this is what I have done till now:
I created an Android Project names as :MyDC
MyDC.java
Code:
package com.super.mydc;
import android.app.Activity;
import android.os.Bundle;
import android.widget.EditText;
import android.widget.TextView;
import android.widget.Button;
import android.view.View;
public class MyDC extends Activity {
private EditText amount1;
private double x=0;
private double y=2.0;
private double z=0;
private TextView tt;
private Button calculate;
/** Called when the activity is first created. */
@Override
public void onCreate(Bundle icicle) {
super.onCreate(icicle);
// We want to view some very simple text, so we need a TextView
TextView tv = new TextView(this);
// Put some text to the newly created TextVIew
tv.setText("Test");
// Tell our Application to display the textView
this.setContentView(tv);
super.onCreate(icicle);
setContentView(R.layout.main);
initControls();
}
private void initControls()
{
amount1=(EditText)findViewById(R.id.amount1);
tt=(TextView)findViewById(R.id.tt);
calculate=(Button)findViewById(R.id.calculate);
calculate.setOnClickListener(new Button.OnClickListener()
{public void onClick
(View v) { calculate();}});
}
private void calculate()
{
x=Double.parseDouble(amount1.getText().toString());
z=x-(x*y/100);
tt.setText(Double.toString(z));
}
}
This is main.xml
Code:
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:orientation="vertical"
android:layout_width="fill_parent"
android:layout_height="fill_parent"
>
<Spinner android:layout_width="match_parent" android:layout_height="wrap_content" android:id="@+id/spinner1"></Spinner>
<TextView
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:text="Enter the price"
/>
<EditText android:layout_height="wrap_content" android:id="@+id/amount1" android:text="" android:layout_width="match_parent"></EditText>
<Button android:text="Calculate Result" android:id="@+id/calculate" android:layout_width="wrap_content" android:layout_height="wrap_content"></Button>
<EditText android:layout_height="wrap_content" android:id="@+id/tt" android:text="" android:layout_width="match_parent"></EditText>
</LinearLayout>
This is string.xml
Code:
<?xml version="1.0" encoding="utf-8"?>
<resources>
<string name="hello">Hi, MyDC!</string>
<string name="app_name">My, DC</string>
<string name="spinner1">Choose discount type</string>
</resources>
This is what I am able to get:
{
"lightbox_close": "Close",
"lightbox_next": "Next",
"lightbox_previous": "Previous",
"lightbox_error": "The requested content cannot be loaded. Please try again later.",
"lightbox_start_slideshow": "Start slideshow",
"lightbox_stop_slideshow": "Stop slideshow",
"lightbox_full_screen": "Full screen",
"lightbox_thumbnails": "Thumbnails",
"lightbox_download": "Download",
"lightbox_share": "Share",
"lightbox_zoom": "Zoom",
"lightbox_new_window": "New window",
"lightbox_toggle_sidebar": "Toggle sidebar"
}
I am able to calculate discount on the button click, BUT i have hardcoded the discount rate.
I want to select discount rate based on the dropdown menu (I don't know how to set dropdown values with different discount rate in this problem)
In the dropdown menu I would like to have values like this:
Type 1 discount
Type 2 discount
Type 3 discount
Here is the respective discount rate for the above drop-down values:
Type 1 discount - 10%
Type 2 discount - 15%
Type 3 discount - 18%
PLZ HELP ME

Ok somehow I was able to add spinner tool on my application.
Now the question is how to select discount rate based on selected value from spinner.
PLZ HELP ME WITH THE CODE
Here is my current code:
MyDC.java
Code:
package com.super.mydc;
import android.app.Activity;
import android.os.Bundle;
import android.widget.ArrayAdapter;
import android.widget.EditText;
import android.widget.Spinner;
import android.widget.TextView;
import android.widget.Button;
import android.view.View;
public class MyDC extends Activity {
private EditText amount1;
private double x=0;
private double y=2.0;
private double z=0;
private TextView tt;
private Button calculate;
/** Called when the activity is first created. */
@Override
public void onCreate(Bundle icicle) {
super.onCreate(icicle);
// We want to view some very simple text, so we need a TextView
TextView tv = new TextView(this);
// Put some text to the newly created TextVIew
tv.setText("Test");
// Tell our Application to display the textView
this.setContentView(tv);
super.onCreate(icicle);
setContentView(R.layout.main);
Spinner spinner = (Spinner) findViewById(R.id.spinner);
ArrayAdapter<CharSequence> adapter = ArrayAdapter.createFromResource(
this, R.array.planets_array, android.R.layout.simple_spinner_item);
adapter.setDropDownViewResource(android.R.layout.simple_spinner_dropdown_item);
spinner.setAdapter(adapter);
initControls();
}
private void initControls()
{
amount1=(EditText)findViewById(R.id.amount1);
tt=(TextView)findViewById(R.id.tt);
calculate=(Button)findViewById(R.id.calculate);
calculate.setOnClickListener(new Button.OnClickListener()
{public void onClick
(View v) { calculate();}});
}
private void calculate()
{
x=Double.parseDouble(amount1.getText().toString());
z=x-(x*y/100);
tt.setText(Double.toString(z));
}
}
main.xml
Code:
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:orientation="vertical"
android:layout_width="fill_parent"
android:layout_height="fill_parent"
>
<Spinner android:layout_width="match_parent" android:layout_height="wrap_content" android:id="@+id/spinner1"></Spinner>
<TextView
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:layout_marginTop="10dip"
android:text="@string/planet_prompt"
/>
<Spinner
android:id="@+id/spinner"
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:prompt="@string/planet_prompt"
/>
<TextView
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:text="Enter the price"
/>
<EditText android:layout_height="wrap_content" android:id="@+id/amount1" android:text="" android:layout_width="match_parent"></EditText>
<Button android:text="Calculate Result" android:id="@+id/calculate" android:layout_width="wrap_content" android:layout_height="wrap_content"></Button>
<EditText android:layout_height="wrap_content" android:id="@+id/tt" android:text="" android:layout_width="match_parent"></EditText>
</LinearLayout>
strings.xml
Code:
<?xml version="1.0" encoding="utf-8"?>
<resources>
<string name="hello">Hi, MyDC!</string>
<string name="app_name">My, DC</string>
<string name="spinner1">Choose a planet</string>
<string name="planet_prompt">Choose a planet</string>
<string-array name="planets_array">
<item>10% discount A</item>
<item>15% discount B</item>
<item>18% discount C</item>
</string-array>
</resources>

Anyone ? Please Help ?

Im sorry to not be of very much help I studied java as a highschool unfortunately it was senior year and I am good at slacking. I would like to add suggestions though. first off i would try to find someway of implementing a way to get closer increments such as 5 or 1 %. such as a text box. let me sift through your code and see what i can see. are you having specific errors or what. we need some info.

Ok i looked at your code and im having a hard time reading it just because it isnt the norm that I look at. first off ya need to name your variables more recognizable things then x and y. that will make coding immensely more easy. also I am not seeing where you gathered the information from the drop down or spinner. at some point in the code you have to collect the information from the drop down or spinner and use it for the percent. also i didn't see any point where you gave the drop down any values. if you have any questions or anything feel free to pm I have xda app on my phone so even if not im not online ill get a notification on my phone.

{SBR}_L3GION said:
Ok i looked at your code and im having a hard time reading it just because it isnt the norm that I look at. first off ya need to name your variables more recognizable things then x and y. that will make coding immensely more easy. also I am not seeing where you gathered the information from the drop down or spinner. at some point in the code you have to collect the information from the drop down or spinner and use it for the percent. also i didn't see any point where you gave the drop down any values. if you have any questions or anything feel free to pm I have xda app on my phone so even if not im not online ill get a notification on my phone.
Click to expand...
Click to collapse
Hi,
Yes, I know I haven't defined values to drop down because that is the thing I need help with.
I also posted above this:
"Now the question is how to select discount rate based on selected value from spinner.
PLZ HELP ME WITH THE CODE"
I need help - How to define discount rate based on selection of drop down values.
Please help me with the code....

I also tried doing this quite awhile with an app I was writing and then discovered I had not enough experience to with the android system to write the program I should look it up and fix both of our programs but I've had a migraine for days and I'm just getting close to sleeping but when I get a chance I will look up giving values to the drop down and collecting them unless you want to google it first.
Sent from my Synergized xda Premium Evo

I have tried to find the solution on google but didn't get anything but somehow from google I was able to do (whatever I did above)
thanks, I think that would be great, if you can test my program on your side by that we both will be on the same page.
That's fine, you can test it whenever you get some time.
I appreciate your help!

I would setup radio buttons for the discount percentages
0 10% 0 20% etc.
Name each radio button and use a case statement to set a float to it's value:
switch(radioGroupName) {
case 10Percent:
int discountValue = .10
break;
...
Then do something like:
int discountedAmount = usersAmount - (usersAmount * discountValue);

Try this code.
myDC.java
Code:
package com.mydc;
import android.app.Activity;
import android.os.Bundle;
import android.view.View;
import android.view.View.OnClickListener;
import android.widget.AdapterView;
import android.widget.ArrayAdapter;
import android.widget.Button;
import android.widget.EditText;
import android.widget.Spinner;
import android.widget.AdapterView.OnItemSelectedListener;
import android.widget.TextView;
import android.widget.Toast;
public class myDC extends Activity {
double initial_price;
double discount;
double final_price;
/** Called when the activity is first created. */
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.main);
Spinner spinner = (Spinner) findViewById(R.id.spinner1);
ArrayAdapter<CharSequence> adapter = ArrayAdapter.createFromResource(
this, R.array.discount, android.R.layout.simple_spinner_item);
adapter.setDropDownViewResource(android.R.layout.simple_spinner_dropdown_item);
spinner.setAdapter(adapter);
spinner.setOnItemSelectedListener(new OnItemSelectedListener(){
@Override
public void onItemSelected(AdapterView<?> parent, View view, int pos, long id) {
if (pos==0){
discount=10;
}
else if (pos==1){
discount=15;
}
else if (pos==2){
discount=18;
}
}
@Override
public void onNothingSelected(AdapterView<?> arg0) {
// TODO Auto-generated method stub
}
});
Button calculate = (Button) findViewById(R.id.calculate);
calculate.setOnClickListener(new OnClickListener(){
@Override
public void onClick(View v) {
EditText amount1 = (EditText) findViewById(R.id.amount1);
if (amount1.length()>0 ) {
initial_price=Double.parseDouble(amount1.getText().toString());
TextView final_price_text = (TextView) findViewById(R.id.final_price);
final_price=initial_price-(initial_price*discount/100);
final_price_text.setText("Final Price : "+final_price);
}
else {
Toast.makeText(getBaseContext(), "Please enter price", Toast.LENGTH_SHORT).show();
}
}
});
}
}
main.xml
Code:
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout
xmlns:android="http://schemas.android.com/apk/res/android"
android:orientation="vertical"
android:layout_width="fill_parent"
android:layout_height="fill_parent">
<Spinner
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:id="@+id/spinner1"></Spinner>
<TextView
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:text="Enter the price" />
<EditText
android:layout_height="wrap_content"
android:id="@+id/amount1"
android:text=""
android:layout_width="match_parent"
android:numeric="decimal"></EditText>
<Button
android:text="Calculate Result"
android:id="@+id/calculate"
android:layout_width="wrap_content"
android:layout_height="wrap_content"></Button>
<TextView
android:layout_height="wrap_content"
android:textAppearance="?android:attr/textAppearanceLarge"
android:layout_width="fill_parent"
android:id="@+id/final_price"></TextView>
</LinearLayout>
strings.xml
Code:
<?xml version="1.0" encoding="utf-8"?>
<resources>
<string name="hello">Hello World, main!</string>
<string name="app_name">myDC</string>
<string-array name="discount">
<item>10% discount A</item>
<item>15% discount B</item>
<item>18% discount C</item>
</string-array>
</resources>

Re: Need Help
Hello nemoc 23 ,
Firstly thank you very much for replying back with a solution.
It did work and solved my problem upto some extend.
Now what I only want 2 things to be done:
1) Right now, if we enter price in decimal or anything, if the final result is in decimal, it is being displayed as EXACT something like 99.9999999
How to limit the RESULT upto 2 decimal points only ?
2) What I am trying to do is to have this calculator on 3 different pages (in each page I will just modify the discounted rate). So I want a homepage (which will work as MENU) with 3 or 4 buttons and each button should be connected with specific page that will have ITS OWN above discount calculator.
Could you please show me how to create a homepage screen (which will work as MENU) and 3 or 4 buttons on it which are linked with different pages (in each page you can copy the same above calculator and I will modify the rate by myself)
thank you

Why 3 pages? Just do this:
Enter discount amount: ___________
Enter discount rate:______
Discounted Amount: ___________
Easy peasy.

Rootstonian said:
Why 3 pages? Just do this:
Enter discount amount: ___________
Enter discount rate:______
Discounted Amount: ___________
Easy peasy.
Click to expand...
Click to collapse
I know it is easy but it is not what I am looking for. My requirement is what I posted above. Thanks

Help
Hello nemoc 23 ,
Just giving you an update. I did try the tutorial you asked me to try. I am having some problem in it which you can see here: http://forum.xda-developers.com/showthread.php?p=15612542
Coming back my question (this calculator topic) - I created a screen layout to give you an idea what I want to do and need your help with.
This is what I want to do:
In this each button click will open separate page (or I guess it is called activity). I have mentioned on button what each button will open.
Please help me. thanks

Intent i = new Intent(this, calculator1.class);
startActivity(i);
You are still better off creating just ONE new Activity and passing to it which calculator you want to run. It is poor programming to code 3 activities when one will suffice. You'll need "extras" to do this.

Need Help
Ok somehow I was able to code for this problem but I am not getting desired output.
I have 3 buttons on my welcome screen "calculator", "calculator2", "exit" - My buttons are not working, I don't know why.
**Below is my complete code / programs:**
**welcome.java**
Code:
package com.testcalculator;
import android.app.Activity;
import android.content.Intent;
import android.os.Bundle;
import android.view.View;
import android.view.View.OnClickListener;
import android.widget.Button;
public class welcome extends Activity implements OnClickListener
{
public void onCreate(Bundle savedInstanceState)
{
super.onCreate(savedInstanceState);
setContentView(R.layout.welcome1);
//////// MENU //////////
Button playBtn = (Button) findViewById(R.id.playBtn);
playBtn.setOnClickListener(this);
Button playBtn2 = (Button) findViewById(R.id.playBtn);
playBtn2.setOnClickListener(this);
Button exitBtn = (Button) findViewById(R.id.exitBtn);
exitBtn.setOnClickListener(this);
}
/**
* Listener for game menu
*/
public void onClick(View v) {
Intent i;
switch (v.getId()){
case R.id.playBtn :
i = new Intent(this, testcalculator.class);
startActivity(i);
break;
case R.id.playBtn2 :
i = new Intent(this, testcalculator2.class);
startActivity(i);
break;
case R.id.exitBtn :
finish();
break;
}
}
}
**welcome1.xml**
Code:
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:orientation="vertical"
android:layout_width="fill_parent"
android:layout_height="fill_parent"
>
<Button
android:id ="@+id/playBtn"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="Calculator"
/>
<Button
android:id ="@+id/playBtn2"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="Calculator2"
/>
<Button
android:id ="@+id/exitBtn"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="Exit"
/>
</LinearLayout>
**testcalculator.java**
Code:
package com.testcalculator;
import android.app.Activity;
import android.os.Bundle;
import android.view.View;
import android.view.View.OnClickListener;
import android.widget.AdapterView;
import android.widget.ArrayAdapter;
import android.widget.Button;
import android.widget.EditText;
import android.widget.Spinner;
import android.widget.AdapterView.OnItemSelectedListener;
import android.widget.TextView;
import android.widget.Toast;
public class testcalculator extends Activity {
double initial_price;
double discount;
double final_price;
/** Called when the activity is first created. */
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.main);
Spinner spinner = (Spinner) findViewById(R.id.spinner1);
ArrayAdapter<CharSequence> adapter = ArrayAdapter.createFromResource(
this, R.array.discount, android.R.layout.simple_spinner_item);
adapter.setDropDownViewResource(android.R.layout.simple_spinner_dropdown_item);
spinner.setAdapter(adapter);
spinner.setOnItemSelectedListener(new OnItemSelectedListener(){
@Override
public void onItemSelected(AdapterView<?> parent, View view, int pos, long id) {
if (pos==0){
discount=10;
}
else if (pos==1){
discount=15;
}
else if (pos==2){
discount=18;
}
}
@Override
public void onNothingSelected(AdapterView<?> arg0) {
// TODO Auto-generated method stub
}
});
Button calculate = (Button) findViewById(R.id.calculate);
calculate.setOnClickListener(new OnClickListener(){
@Override
public void onClick(View v) {
EditText amount1 = (EditText) findViewById(R.id.amount1);
if (amount1.length()>0 ) {
initial_price=Double.parseDouble(amount1.getText().toString());
TextView final_price_text = (TextView) findViewById(R.id.final_price);
final_price=initial_price-(initial_price*discount/100);
final_price_text.setText("Final Price : "+final_price);
}
else {
Toast.makeText(getBaseContext(), "Please enter price", Toast.LENGTH_SHORT).show();
}
}
});
}
}
**testcalculator.xml**
Code:
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:orientation="vertical"
android:layout_width="fill_parent"
android:layout_height="fill_parent"
>
<Spinner
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:id="@+id/spinner1"></Spinner>
<TextView
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:text="Enter the price" />
<EditText
android:layout_height="wrap_content"
android:id="@+id/amount1"
android:text=""
android:layout_width="match_parent"
android:numeric="decimal"></EditText>
<Button
android:text="Calculate Result"
android:id="@+id/calculate"
android:layout_width="wrap_content"
android:layout_height="wrap_content"></Button>
<TextView
android:layout_height="wrap_content"
android:textAppearance="?android:attr/textAppearanceLarge"
android:layout_width="fill_parent"
android:id="@+id/final_price"></TextView>
</LinearLayout>
**testcalculator2.java**
Code:
package com.testcalculator;
import android.app.Activity;
import android.os.Bundle;
import android.view.View;
import android.view.View.OnClickListener;
import android.widget.AdapterView;
import android.widget.ArrayAdapter;
import android.widget.Button;
import android.widget.EditText;
import android.widget.Spinner;
import android.widget.AdapterView.OnItemSelectedListener;
import android.widget.TextView;
import android.widget.Toast;
public class testcalculator2 extends Activity {
double initial_price;
double discount2;
double final_price2;
/** Called when the activity is first created. */
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.main);
Spinner spinner = (Spinner) findViewById(R.id.spinner2);
ArrayAdapter<CharSequence> adapter = ArrayAdapter.createFromResource(
this, R.array.discount2, android.R.layout.simple_spinner_item);
adapter.setDropDownViewResource(android.R.layout.simple_spinner_dropdown_item);
spinner.setAdapter(adapter);
spinner.setOnItemSelectedListener(new OnItemSelectedListener(){
@Override
public void onItemSelected(AdapterView<?> parent, View view, int pos, long id) {
if (pos==0){
discount2=20;
}
else if (pos==1){
discount2=25;
}
else if (pos==2){
discount2=28;
}
}
@Override
public void onNothingSelected(AdapterView<?> arg0) {
// TODO Auto-generated method stub
}
});
Button calculate2 = (Button) findViewById(R.id.calculate2);
calculate2.setOnClickListener(new OnClickListener(){
@Override
public void onClick(View v) {
EditText amount2 = (EditText) findViewById(R.id.amount2);
if (amount2.length()>0 ) {
initial_price=Double.parseDouble(amount2.getText().toString());
TextView final_price_text = (TextView) findViewById(R.id.final_price2);
final_price2=initial_price-(initial_price*discount2/100);
final_price_text.setText("Final Price : "+final_price2);
}
else {
Toast.makeText(getBaseContext(), "Please enter price", Toast.LENGTH_SHORT).show();
}
}
});
}
}
**testcalculator2.xml**
Code:
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:orientation="vertical"
android:layout_width="fill_parent"
android:layout_height="fill_parent"
>
<Spinner
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:id="@+id/spinner2"></Spinner>
<TextView
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:text="Enter the price" />
<EditText
android:layout_height="wrap_content"
android:id="@+id/amount2"
android:text=""
android:layout_width="match_parent"
android:numeric="decimal"></EditText>
<Button
android:text="Calculate Result"
android:id="@+id/calculate2"
android:layout_width="wrap_content"
android:layout_height="wrap_content"></Button>
<TextView
android:layout_height="wrap_content"
android:textAppearance="?android:attr/textAppearanceLarge"
android:layout_width="fill_parent"
android:id="@+id/final_price2"></TextView>
</LinearLayout>
**AndroidManifest.xml**
Code:
<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
package="com.testcalculator"
android:versionCode="1"
android:versionName="1.0">
<application android:icon="@drawable/icon" android:label="@string/app_name">
<activity android:name=".welcome"
android:label="@string/app_name">
<intent-filter>
<action android:name="android.intent.action.MAIN" />
<category android:name="android.intent.category.LAUNCHER" />
</intent-filter>
</activity>
<activity android:name=".testcalculator" />
<activity android:name=".testcalculator2" />
</application>
</manifest>
**strings.xml**
Code:
<?xml version="1.0" encoding="utf-8"?>
<resources>
<string name="hello">Hello World, testcalculator!</string>
<string name="app_name">testcalculator</string>
<string-array name="discount">
<item>10% discount A</item>
<item>15% discount B</item>
<item>18% discount C</item>
</string-array>
<string-array name="discount2">
<item>20% discount A</item>
<item>25% discount B</item>
<item>28% discount C</item>
</string-array>
</resources>
**main.xml**
Code:
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:orientation="vertical"
android:layout_width="fill_parent"
android:layout_height="fill_parent"
>
<TextView
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:text="@string/hello"
/>
</LinearLayout>
When I click Button1 "Calculator" - I get error saying ""The application testcalculator (process com.testcalculator) has stopped unexpectedly. Please try again.""
Button2 "Calculator2" doesn't do anything and same with 3rd button "exit:
**Please help me!!!**

You got a couple options. First instead of the startActivity() throw in a Toast so you can see if your onClick() is ok. You can also throw some inline clicklisteners (anonymous inner class) inside the setOnClickListener() instead of using 'this'. I find that way is a bit easier to organize.
Annd might I suggest you follow the Java guidelines for capitalisation of class names. Its confusing when reading your code and seeing testcalculator.class when usually instances of objects are lower case while the class name is capitalized. Like TestCalculator.class
From something awesome

[Q] Choose a string in spinner

Hey guys!
I am working on my first app, cut me some slack for asking please .
So I'm stuck on a little problem:
I have a reader activity and I put a spinner on top of the screen to choose the string where the text comes from:
Code:
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:orientation="vertical"
android:layout_width="fill_parent"
android:layout_height="fill_parent">
<Spinner
android:id="@+id/kapitelspinner"
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:prompt="@string/kapitel_prompt" />
<ScrollView android:layout_width="wrap_content"
android:layout_height="wrap_content">
<TextView
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:text="@string/kapitel1"
/>
</ScrollView>
</LinearLayout>
The TextView in the ScrollView is supposed to be the selected text from the spinner.
Code:
package com.asm.reader;
import android.app.Activity;
import android.os.Bundle;
import android.widget.ArrayAdapter;
import android.widget.Spinner;
public class BookActivity extends Activity {
static final private int CHOOSE_KAPITEL = 0;
/** Called when the activity is first created. */
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.book_activity);
Spinner spinner = (Spinner) findViewById(R.id.kapitelspinner);
ArrayAdapter<CharSequence> adapter = ArrayAdapter.createFromResource(
this, R.array.kapitel_array, android.R.layout.simple_spinner_item);
adapter.setDropDownViewResource(android.R.layout.simple_spinner_dropdown_item);
spinner.setAdapter(adapter);
spinner.setOnItemSelectedListener(new MyOnItemSelectedListener());
}
}
Code:
package com.asm.reader;
import android.view.View;
import android.widget.AdapterView;
import android.widget.AdapterView.OnItemSelectedListener;
import android.widget.Toast;
public class MyOnItemSelectedListener implements OnItemSelectedListener {
public void onItemSelected(AdapterView<?> parent,
View view, int pos, long id) {
Toast.makeText(parent.getContext(),
parent.getItemAtPosition(pos).toString(), Toast.LENGTH_LONG).show();
}
public void onNothingSelected(AdapterView parent) {
// Do nothing.
}
}
I'm trying to make the spinner choose the string of the textview but i have no idea how to do it. (Already did the toast part)
If anyone could help me it would be greatly appreciated!
Thanks !

bump. the last problem im stuck on

The way I understand what you're trying to do is select an item from the spinner, and set the TextView according to the selected spinner item.
If that is the case you will, for starters, need to set an id attribute for the TextView in the layout xml file.
Then within your onItemSelected() method you need to create a reference to the TextView the same way you did it with the spinner; using the findViewById() method.
Then using that reference you can set the text of the TextView using the same string you got when you created the Toast notification.
Hope that helps!

How to set the background of an activity

Ok so im just practising my android skills. What I did was basically make an app that lets the user choose what image to set as the wallpaper or the background of the app.
Ive set the wallpaper up but couldnt find a way to setting the background up for the app/activity.
XML:
Code:
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:orientation="vertical" >
<ImageView
android:id="@+id/IVDisplay"
android:layout_width="200dp"
android:layout_height="200dp"
android:layout_gravity="center"
android:src="@drawable/bentley" />
<HorizontalScrollView
android:id="@+id/scroll"
android:layout_width="fill_parent"
android:layout_height="100dp" >
<LinearLayout
android:id="@+id/linearlayout"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:orientation="horizontal" >
<ImageView
android:id="@+id/img1"
android:layout_width="100dp"
android:layout_height="100dp"
android:padding="10dp"
android:src="@drawable/bentley" />
<ImageView
android:id="@+id/img2"
android:layout_width="100dp"
android:layout_height="100dp"
android:padding="10dp"
android:src="@drawable/bugatti" />
<ImageView
android:id="@+id/img3"
android:layout_width="100dp"
android:layout_height="100dp"
android:padding="10dp"
android:src="@drawable/dodge" />
<ImageView
android:id="@+id/img4"
android:layout_width="100dp"
android:layout_height="100dp"
android:padding="10dp"
android:src="@drawable/ic_launcher" />
<ImageView
android:id="@+id/img5"
android:layout_width="100dp"
android:layout_height="100dp"
android:padding="10dp"
android:src="@drawable/rollsroyce" />
</LinearLayout>
</HorizontalScrollView>
<Button
android:id="@+id/wallpaperbutton"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="Set as wallpaper" />
<Button
android:id="@+id/bkgbutton"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="Set as Background" />
</LinearLayout>
Java:
Code:
package com.examples.hello;
import java.io.IOException;
import java.io.InputStream;
import android.app.Activity;
import android.app.WallpaperManager;
import android.graphics.Bitmap;
import android.graphics.BitmapFactory;
import android.os.Bundle;
import android.view.View;
import android.view.View.OnClickListener;
import android.widget.Button;
import android.widget.ImageView;
public class PAGEONE extends Activity implements OnClickListener {
ImageView display;
int tophone;
[user=439709]@override[/user]
protected void onCreate(Bundle savedInstanceState) {
// TODO Auto-generated method stub
super.onCreate(savedInstanceState);
setContentView(R.layout.bkgd);
display = (ImageView) findViewById(R.id.IVDisplay);
tophone = R.drawable.bentley;
Button wallpap = (Button) findViewById(R.id.wallpaperbutton);
Button bkg = (Button) findViewById(R.id.bkgbutton);
ImageView img1 = (ImageView) findViewById(R.id.img1);
ImageView img2 = (ImageView) findViewById(R.id.img2);
ImageView img3 = (ImageView) findViewById(R.id.img3);
ImageView img4 = (ImageView) findViewById(R.id.img4);
ImageView img5 = (ImageView) findViewById(R.id.img5);
img1.setOnClickListener(this);
img2.setOnClickListener(this);
img3.setOnClickListener(this);
img4.setOnClickListener(this);
img5.setOnClickListener(this);
wallpap.setOnClickListener(this);
}
[user=439709]@override[/user]
public void onClick(View v) {
// TODO Auto-generated method stub
switch (v.getId()) {
case R.id.img1:
display.setImageResource(R.drawable.bentley);
tophone = R.drawable.bentley;
break;
case R.id.img2:
display.setImageResource(R.drawable.bugatti);
tophone = R.drawable.bugatti;
break;
case R.id.img3:
display.setImageResource(R.drawable.dodge);
tophone = R.drawable.dodge;
break;
case R.id.img4:
display.setImageResource(R.drawable.ic_launcher);
tophone = R.drawable.ic_launcher;
break;
case R.id.img5:
display.setImageResource(R.drawable.rollsroyce);
tophone = R.drawable.rollsroyce;
break;
case R.id.wallpaperbutton:
InputStream yea = getResources().openRawResource(tophone);
Bitmap hmm = BitmapFactory.decodeStream(yea);
WallpaperManager mywallpaper = WallpaperManager.getInstance(getApplicationContext ());
try{
mywallpaper.setResource(tophone);
}catch(IOException e){
e.printStackTrace();
}
}
}
}
I dont know what methods to use. I was thinking of setting up individual pictures as the layouts (so I'd have 5 extra layouts since I have 5 pictures), but that wouldn't make any sense.

You need to give your linearlayout an id and then find the view by normal ways and use:
yourLayout.setBackgroundDrawable(Drawable d);
Code:
LinearLayout linLay = (LinearLayout) findViewById(R.id.theLinearLayoutId);
//set background to a color
linLay.setBackgroundColor("#404040");
//set background to a drawable
linLay.setBackgroundDrawable(drawableItem);
//set background to a resource
linLay.setBackgroundResource(R.id.backgroundResource);

Or just
Code:
getWindow().getDecorView().setBackgroundDrawable(*yourDrawable*);
After setContentView

Thanks for your help guys. I followed Chris95x8's advice since its only one line of code and really, who can deny one line of code??
Anyways, took a few tries to make it work but finally did it. I put that statement after the set content view but got errors and plus that statement is deprecated so I used this methd:
getWindow().getDecorView().setBackgroundResource();
I just pasted it into the switch statement I created earlier:
case R.id.bkgbutton:
getWindow().getDecorView().setBackgroundResource(tophone);
break;
Whilst I was at it, created a few toasts letting the user know the background/wallpaper has been set.
One thing I dont understand, what does it mean by context? For example, when using the toast method:
Toast df = Toast.makeText(context, text, duration)
What does the context mean in the bracket/parenthesis ?

TwilightLoz said:
Thanks for your help guys. I followed Chris95x8's advice since its only one line of code and really, who can deny one line of code??
Anyways, took a few tries to make it work but finally did it. I put that statement after the set content view but got errors and plus that statement is deprecated so I used this methd:
getWindow().getDecorView().setBackgroundResource();
I just pasted it into the switch statement I created earlier:
case R.id.bkgbutton:
getWindow().getDecorView().setBackgroundResource(tophone);
break;
Whilst I was at it, created a few toasts letting the user know the background/wallpaper has been set.
One thing I dont understand, what does it mean by context? For example, when using the toast method:
Toast df = Toast.makeText(context, text, duration)
What does the context mean in the bracket/parenthesis ?
Click to expand...
Click to collapse
Hi,
Please check this out to know what the Context class does - http://stackoverflow.com/questions/3572463/what-is-context-in-android
Good luck

Stackview Widget - Items not loading

I've tried to create simple dialer widget that will get contacts from contact book, put them into stackview and when clicked create a popup where you can call or create a message. I worked well as an application, but when I turned it into actual widget, I've encountered something weird. Despite all the methods firing, the items are not updated and stay on loading layout.
I've compared it to the example, tried to switch parts of code and nothing works. Even funnier, my code works perfectly when I put it in example widget, but example code doesn't work in mine. The same thing happens for listview and gridview. Is there any other file I should edit?
I provide the code, layouts and manifest. Logcat shows all methods firing in right order, so there's nothing to see there.
WidgetProvider.java
Code:
public class WidgetProvider extends AppWidgetProvider {
@Override
public void onUpdate(Context context, AppWidgetManager appWidgetManager,
int[] appWidgetIds){
Log.d("WIDGET", "Called onUpdate()");
for (int i = 0; i < appWidgetIds.length; ++i){
// Set up the intent that starts the StackViewService, which will
// provide the views for this collection.
Intent intent = new Intent(context, WidgetService.class);
// Add the app widget ID to the intent extras.
intent.putExtra(AppWidgetManager.EXTRA_APPWIDGET_ID, appWidgetIds[i]);
intent.setData(Uri.parse(intent.toUri(Intent.URI_INTENT_SCHEME)));
// Instantiate the RemoteViews object for the app widget layout.
RemoteViews rv = new RemoteViews(context.getPackageName(), R.layout.main);
rv.setRemoteAdapter(R.id.stackView, intent);
rv.setEmptyView(R.id.stackView, R.id.emptyView);
appWidgetManager.updateAppWidget(appWidgetIds[i], rv);
Log.d("WIDGET", "Widget updated");
}
super.onUpdate(context, appWidgetManager, appWidgetIds);
}
}
WidgetService.java
Code:
package com.chmis.superdialer;
import java.util.Collections;
import android.content.Context;
import android.content.Intent;
import android.database.Cursor;
import android.provider.ContactsContract;
import android.util.Log;
import android.widget.RemoteViews;
import android.widget.RemoteViewsService;
public class WidgetService extends RemoteViewsService {
@Override
public RemoteViewsFactory onGetViewFactory(Intent intent) {
return new StackRemoteViewsFactory(this.getApplicationContext(), intent);
}
}
class StackRemoteViewsFactory implements RemoteViewsService.RemoteViewsFactory {
Context context;
Intent intent;
public StackRemoteViewsFactory(Context applicationContext, Intent intent) {
this.context = applicationContext;
this.intent = intent;
}
@Override
public void onCreate() {
Log.d("SERVICE", "Called onCreate()");
//Get contact Cursor
Cursor contactCursor = context.getContentResolver().query(
ContactsContract.CommonDataKinds.Phone.CONTENT_URI,
null, null, null, null);
//Get contacts from cursor, store them as Contact objects inside ArrayList
while (contactCursor.moveToNext()) {
String name = contactCursor.getString(contactCursor.getColumnIndex(
ContactsContract.CommonDataKinds.Phone.DISPLAY_NAME));
String phone = contactCursor.getString(contactCursor.getColumnIndex(
ContactsContract.CommonDataKinds.Phone.NUMBER));
long id = contactCursor.getLong(contactCursor.getColumnIndex(
ContactsContract.CommonDataKinds.Phone.CONTACT_ID));
Contact.array.add(new Contact(name, phone, id));
}
//Sort contacts by name
Collections.sort(Contact.array, new ContactComparator(Contact.JOHN_SMITH));
}
@Override
public RemoteViews getViewAt(int position) {
Log.d("SERVICE", "Called getViewAt(" + position + ")");
RemoteViews rv = new RemoteViews(context.getPackageName(), R.layout.main);
rv.setTextViewText(R.id.contactNameTextView, Contact.array.get(position).getDefaultName());
// Return the remote views object.
return rv;
}
@Override
public int getCount() {
Log.d("SERVICE", "Called getCount(), returned " + Contact.array.size());
return Contact.array.size();
}
@Override
public long getItemId(int position) {
return position;
}
@Override
public RemoteViews getLoadingView() {
return null;
}
@Override
public int getViewTypeCount() {
return 0;
}
@Override
public boolean hasStableIds() {
return true;
}
@Override
public void onDataSetChanged() {}
@Override
public void onDestroy() {
Contact.array.clear();
Log.d("SERVICE", "Called onDestroy()");
}
}
main.xml
Code:
<?xml version="1.0" encoding="utf-8"?>
<FrameLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="match_parent"
android:layout_height="match_parent" >
<StackView
android:id="@+id/stackView"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:gravity="center"
android:loopViews="true" />
<TextView
android:id="@+id/emptyView"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:gravity="center"
android:background="@android:color/transparent"
android:textStyle="bold"
android:textColor="#ffffff"
android:text="@string/no_contacts" />
</FrameLayout>
contact_stack_item
Code:
<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:background="@color/transparent_dark" >
<ImageView
android:id="@+id/contactPhotoImageView"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_centerHorizontal="true"
android:layout_centerVertical="true"
android:contentDescription="@string/contact_image_description"
android:src="@drawable/contact_photo_default" />
<TextView
android:id="@+id/contactNameTextView"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_alignBottom="@+id/contactPhotoImageView"
android:layout_alignLeft="@+id/contactPhotoImageView"
android:layout_alignRight="@+id/contactPhotoImageView"
android:background="@color/transparent_dark"
android:gravity="center_horizontal"
android:text="@string/contact_name_placeholder"
android:textColor="@android:color/white" />
</RelativeLayout>
manifest
Code:
<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
package="com.chmis.superdialer"
android:versionCode="1"
android:versionName="1.0" >
<uses-sdk
android:minSdkVersion="14"
android:targetSdkVersion="19" />
<uses-permission android:name="android.permission.READ_CONTACTS" />
<application android:label="@string/app_name" >
<receiver android:name="WidgetProvider" >
<intent-filter>
<action android:name="android.appwidget.action.APPWIDGET_UPDATE" />
</intent-filter>
<meta-data
android:name="android.appwidget.provider"
android:resource="@xml/app_widget_provider_info" />
</receiver>
<service
android:name="WidgetService"
android:exported="false"
android:permission="android.permission.BIND_REMOTEVIEWS" />
</application>
</manifest>
@edit I've copied the whole service code again and now it decided to work. I don't know anything anymore.

[Q] Help needed display fragment with listadapter properly...

Hi guys, I am new to android development and I'm having a little trouble working with a list in fragment.
This is what I'm trying to achieve:
------------------
frag 1
------------------
frag 2 <-- list is here
-----------------
frag 3
-----------------
The list displays 3 strings in one row. This is my fragment code: ( the CustomListViewAdapter is implemented in another file called CustomListViewAdapter.java)
Code:
public class ListActivity extends Fragment{
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
FragmentManager fm = getFragmentManager();
if (fm.findFragmentById(android.R.id.content) == null) {
DataListFragment list = new DataListFragment();
fm.beginTransaction().add(android.R.id.content, list).commit();
}
}
public static class DataListFragment extends ListFragment implements
LoaderManager.LoaderCallbacks<List<Model>> {
CustomListViewAdapter mAdapter;
@Override
public void onActivityCreated(Bundle savedInstanceState) {
super.onActivityCreated(savedInstanceState);
System.out.println("DataListFragment.onActivityCreated");
// Initially there is no data
setEmptyText("No Data Here");
// Create an empty adapter we will use to display the loaded data.
mAdapter = new CustomListViewAdapter(getActivity());
setListAdapter(mAdapter);
// Start out with a progress indicator.
setListShown(false);
}
@Override
public Loader<List<Model>> onCreateLoader(int arg0, Bundle arg1) {
return new DataListLoader(getActivity());
}
}
public static class DataListLoader extends AsyncTaskLoader<List<Model>> {
List<Model> mModels;
public DataListLoader(Context context) {
super(context);
}
@Override
public List<Model> loadInBackground() {
System.out.println("DataListLoader.loadInBackground");
List<Model> entries = new ArrayList<Model>(5);
entries.add(new Model("1", "a","3:48"));
entries.add(new Model("2", "b","4:02"));
entries.add(new Model("3", "c","3:48"));
entries.add(new Model("4", "d","3:52"));
entries.add(new Model("5", "e","3:44"));
return entries;
}
@Override public void deliverResult(List<Model> listOfData) {
...
}
@Override protected void onStartLoading() {
...
}
protected void onReleaseResources(List<Model> apps) {}
}
The 3 fragments are added programmatically in the main activity. MainActivity.java
The problem I am facing is that once the code runs, this fragment 2 overlaps the fragment 1 (both are still visible) that was supposed to be above it. How do I resolve this issue? Please help me figure this out! I believe I'm doing something wrong while adding this fragment.
This is the mainactivity.java
Code:
public class MainActivity extends Activity{
@Override
public void onCreate(Bundle savedInstanceState){
super.onCreate(savedInstanceState);
setContentView(R.layout.main_layout);
FragmentManager fragmentManager = getFragmentManager();
FragmentTransaction fragmentTransaction = fragmentManager.beginTransaction();
fragmentTransaction.add(R.id.info_fragment, new InfoActivity());//frag 1
fragmentTransaction.add(R.id.list_fragment, new listActivity()); // frag 2
fragmentTransaction.add(R.id.controls_fragment, new ControlsActivity()); //frag 3
fragmentTransaction.commit();
}
}

code_name said:
Hi guys, I am new to android development and I'm having a little trouble working with a list in fragment.
Click to expand...
Click to collapse
The layout and views along with the layoutParams control how it looks, the fragments just nest inside the views, that you reference with your resource idents, so however it looks is probably based of the layout or layout parameters that are set in the xml layout

deanwray said:
The layout and views along with the layoutParams control how it looks, the fragments just nest inside the views, that you reference with your resource idents, so however it looks is probably based of the layout or layout parameters that are set in the xml layout
Click to expand...
Click to collapse
I doubt there is any problem with the xml layout. Here is the main layout file:
Code:
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http//schemas.android.com/apk/res/android"
android:id="@+id/linlayname"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:orientation="vertical" >
<FrameLayout
android:id="@+id/info_fragment"
android:layout_weight="3"
android:layout_width="match_parent"
android:layout_height="0dp" >
</FrameLayout>
<FrameLayout
android:id="@+id/list_fragment"
android:layout_weight="4"
android:layout_width="match_parent"
android:layout_height="0dp" >
</FrameLayout>
<FrameLayout
android:id="@+id/controls_fragment"
android:layout_weight="2"
android:layout_width="match_parent"
android:layout_height="0dp" >
</FrameLayout>
</LinearLayout>
And this is the list xml:
Code:
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http//schemas.android.com/apk/res/android"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:orientation="vertical" >
<ListView
android:id="@android:id/list"
android:layout_width="fill_parent"
android:layout_height="wrap_content">
</ListView>
</LinearLayout>

code_name said:
I doubt there is any problem with the xml layout. Here is the main layout file:
Click to expand...
Click to collapse
Are you sure you are using android:layout_weight properly ?
It would first occur to me that not all the views (3 that contain the fragments) should/would be variable ... but it suggests they are ? weight is of the unused remainder space, so I would maybe suggest a weight of 0,1,0 meaning the 1st and last you set to wrap_content and they are variable based on content... the middle using a weight of 1 uses any space remaining
so
Code:
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http//schemas.android.com/apk/res/android"
android:id="@+id/linlayname"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:orientation="vertical" >
<FrameLayout
android:id="@+id/info_fragment"
android:layout_width="match_parent"
android:layout_height="wrap_content" >
</FrameLayout>
<FrameLayout
android:id="@+id/list_fragment"
android:layout_weight="1"
android:layout_width="match_parent"
android:layout_height="0dp" >
</FrameLayout>
<FrameLayout
android:id="@+id/controls_fragment"
android:layout_width="match_parent"
android:layout_height="wrap_content" >
</FrameLayout>
</LinearLayout>

deanwray said:
Are you sure you are using android:layout_weight properly ?
It would first occur to me that not all the views (3 that contain the fragments) should/would be variable ... but it suggests they are ? weight is of the unused remainder space, so I would maybe suggest a weight of 0,1,0 meaning the 1st and last you set to wrap_content and they are variable based on content... the middle using a weight of 1 uses any space remaining
so...
Click to expand...
Click to collapse
Yes that is the way I want it laid out, it looks better now, but the main problem still remains. The listActivity (the middle fragment) starts from the top of the screen and overlaps the first fragment (first one is visible under the list).I think I am adding the fragment at the wrong place?

code_name said:
Yes that is the way I want it laid out, it looks better now, but the main problem still remains. The listActivity (the middle fragment) starts from the top of the screen and overlaps the first fragment (first one is visible under the list).I think I am adding the fragment at the wrong place?
Click to expand...
Click to collapse
BTW I think I have flu atm (or a man cold, either way it would kill a woman) so double check whatever I say
Erm, not sure what your doing with ListActivity onCreate() your doing fragment transactions in there ? But will it not always be null when loading anything ? onCreateView() is where it would return the new view to the fragmentManager for attaching... so when it does the transaction in ListActivity your also using android.R.id.content which is a base id for the area that an app runs in (also happens to be a frameLayout) which is what you problem is... personally I would think and design out of this problem a little different ... if you want a chat hit me up on hangouts, happy to help!