Hi,
in my simple app i have an activity with some textviews and a single imageview.
I'm trying to understand how to dynamically change the content of the imageview in my linear layout. I have a linearlayout and i only need to change the image in it (based on the logic of the underlying application) and similarly the text of the textviews. The pictures are .png files that i have put in res/drawable.
It seems to me that the only way is to use an adapter (simpleadapter) but i struggle to find an example of source code as all the ones i found so far refer to more complex adapters (e.g. simplecursoradapter). Anyway i'm very new to these concepts (adapters, helpers, etc.).
Do i really need to define and use AdapterView (or a more specific subclass?) or if if i keep the image files in res/drawable there is a more straightforward way to dynamically change the ImageView?
Thanks in advance,
x70
ImageView iv = (ImageView)findViewById(R.id.myimageview);
iv.setImageResource(resId);
where resId = R.drawable.mypng
With the textviews is similar, just call setText.
Thanks a lot janfsd. That was really easy...
I did actually try before in that way but i thought i needed also to explicitly set the view (eg via setContentView) and it didnt work; i didn't realise that there is no need for that.
still its not clear to me when do i need to use setContentView, but i made good progress!
Cheers,
x70
setContentView is normally used to set the layout(View) of the activity. I have only used it once per activity. Unless you want to change all the Layout of the activity then don't use it more than once, only on the onCreate method after the super call.
So you should only need to use setSomething method which each view should have it.
Hey,
So I'm making an app that needs to display a bitmap or raw (something where X/Y pixels can be modified, so no compression like a jpg).
There's an Activity which contains only an ImageView, I get the Bitmap from the bundle given in the callback from the camera (it's put into the intent before the Activity starts), then I set it to the ImageView in onCreate of this new Activity (which is basically only an ImageView).
For some reason, when viewing this Activity, the picture is of EXTREMELY low quality. Like, tons of jaggies, like it's a thumbnail or something and is force-scaled up to the screen size. The image isn't really like this, though, when I view it in my gallery it's crystal clear. So why is the quality being dragged down to all hell when I set it in the ImageView? I don't care about the performance constraints, this isn't a production app.
I feel there's some quality control function in the ImageView or something, but I have no idea what. Can somebody tell me the "why" or the "fix" - plzzzz - I'm on a really truncated time schedule and haven't had much luck with this camera for too long .
TIA
Syndacate said:
Hey,
So I'm making an app that needs to display a bitmap or raw (something where X/Y pixels can be modified, so no compression like a jpg).
There's an Activity which contains only an ImageView, I get the Bitmap from the bundle given in the callback from the camera (it's put into the intent before the Activity starts), then I set it to the ImageView in onCreate of this new Activity (which is basically only an ImageView).
For some reason, when viewing this Activity, the picture is of EXTREMELY low quality. Like, tons of jaggies, like it's a thumbnail or something and is force-scaled up to the screen size. The image isn't really like this, though, when I view it in my gallery it's crystal clear. So why is the quality being dragged down to all hell when I set it in the ImageView? I don't care about the performance constraints, this isn't a production app.
I feel there's some quality control function in the ImageView or something, but I have no idea what. Can somebody tell me the "why" or the "fix" - plzzzz - I'm on a really truncated time schedule and haven't had much luck with this camera for too long .
TIA
Click to expand...
Click to collapse
what other info does the camera intent return, what extras?
alostpacket said:
what other info does the camera intent return, what extras?
Click to expand...
Click to collapse
How do I check?
I used somebody else's tutorial to learn that the URI is in the 'data' of the bundle.
I tried checking earlier by using its to-string, but that just gave me the container size.
Syndacate said:
How do I check?
I used somebody else's tutorial to learn that the URI is in the 'data' of the bundle.
I tried checking earlier by using its to-string, but that just gave me the container size.
Click to expand...
Click to collapse
you probably have the URI to the thumbnail
Post the tutorial you used and some code, shouldn't be too hard to figure out.
alostpacket said:
you probably have the URI to the thumbnail
Post the tutorial you used and some code, shouldn't be too hard to figure out.
Click to expand...
Click to collapse
There's like upteen thousand tutorials that I compiled to make what I have.
I have no "links" anymore.
I got the Intent from the camera in the onActivityResult function after calling the camera. I pulled the bundle from it using the getExtras() function on the intent.
I then passed that intent to the new Intent I made to create my second Activity. I passed it via the putExtras function on the new intent.
In essence, I did;
Code:
Intent in = new Intent();
in.putExtras(incoming_intent_from_camera.getExtras());
And then called my second Activity.
In the onCreate() function of my second Activity, I pull the bitmap data using:
Code:
Bitmap bmp = (Bitmap)getIntent().getExtras().get("data");
There are two things in this Bundle, data (a Bitmap (android.graphics.Bitmap)) and a bitmap-data, which is a boolean.
EDIT:
Yes, it is definitely the URI to the thumbnail, I need the large image URI.
I have a feeling the problem is that it needs the EXTRA_OPTION string, the only issue is, I don't want to save this any place in particular. I'll let the camera save it to the default location on my SDCard. I just want the URI to that full size or something usable.
I can't do:
Code:
intent.putExtra(MediaStore.EXTRA_OPTION, <URI>);
Because I don't have nor want an additional URI to store it... I got to get EXTRA_OPTION to the camera somehow..
Okay, so here's the deal, that apparently nobody was able to help me with ():
- Like alostpacket said, the "data" key in the bundle returned from the camera activity (in the callback) contains the URI to the thumbnail - that's useless unless I'm making an icon or some other small/tiny/low res picture.
I was correct in the fact that it had something to do with putting the EXTRA_OPTION into the extras that I passed off to the camera intent.
This DID come at a price, though. You have to make a temporary place to store the image (you know, because the regular one in the gallery just isn't good enough of or something). And by temporary I kind of mean permanent, it gets overwritten every time (assuming you use the same path), but won't get removed. I am unable to understand this functionality. If somebody could explain it that would be great.
So all in all my intent to the camera looks like this:
Code:
image_path = Environment.getExternalStorageDirectory().getAbsolutePath() + "/tmp_image.jpg";
File img = new File (image_path);
Uri uri = Uri.fromFile(img);
Intent intent = new Intent(MediaStore.ACTION_IMAGE_CAPTURE);
intent.putExtra(MediaStore.EXTRA_OUTPUT, uri);
startActivityForResult(intent, PICTURE_REQUEST);
Where image_path is a private class String and PICTURE_REQUEST is a final String (also class level scope) - which can represent any non-0 number, but is unique to the request (think of it as a request ID).
Then, in the callback function, after checking to make sure the request code is PICTURE_REQUEST, and the resultCode was OK:
Code:
Bitmap bmp = BitmapFactory.decodeFile(image_path);
img_view.setImageBitmap(bmp);
img_view.invalidate();
Where image_path is (a String) wherever the image specified as an extra to the camera activity, img_view is an ImageView display element. The invalidate method will redraw the ImageView.
I hope that helps somebody else stuck in the same position I am.
I'm going to leave this question as "unresolved" because there's one thing I still can't figure out. The "EXTRA_OUTPUT" extra passed to the intent seems like a work-around. All that does is define an alternate path to write the file to, then the callback (or whatever) grabs it from there. It's a hack and a half. There has to be a legit way to grab the full quality image taken with the camera. Whether that's accessing the gallery intent or not I'm not sure, but this is definitely a work around. I hope somebody can provide the answer to that, because a lot of tutorials mention the EXTRA_OUTPUT method, and given what it does, I don't believe that is correct.
Hi guys.
New to Android Development and was wondering if there was some way of taking the users input to create an activity? For example say the user is going through the process of setting up a profile of themself. One of the questions is "how many pets do you have?". The user inputs "4" and then clicks the 'Next' button (which opens the next activity).
How would I take the users input of "4" to create four editText objects in the next activity so that the user can now input the name's of his/her's pets?
I'm an ok-ish programmer (have never touched XML before) so you don't need to go into detail I just don't know how I would access this variable to create the four editText objects. From what I've found you can't add strings to the resources at runtime.
Don't bother replying, I've solved my problem. Just need to create a dynamic layout in JAVA
There are two ways to define Button onclick, one of them is to create instance for BUTTON which defined in XML, then use setOnClickListener() to define private method to deal with What BUTTON was pressed. Another is declare OnClickListener method in XML.
I personal consider it is much easier way to declare onClickLstener method in XML. But I read first way in most of Android coding books.
what is the difference between them?
I thank you in advanced.
sincerely yours Tom
[Q] Beginner: Issues with canvas bitmaps, buttons, and layouts
Hi, I'm hoping people might help me with this more open-ended question. I'm fairly new to programming with little scripting experience.
My problem is that I'm cobbling code together from various separate examples, but trying to implement them into my tests, they don't seem to work together.
Let me show you what my goals are for this experiment:
1) Create Button
2) Generate Images with Button click
3) Drag Images around
So far, I've been able to do create images with drawing bitmaps using canvas and create a working button with the easy drag and drop.
My specific problem is that I can't use the Design tool to create buttons if I use the canvas method of drawing bitmaps because setContentView() needs to be on the canvas.
Here's my onCreate():
Code:
GenerateItem ourView;
Button genButton;
LinearLayout myLinearLayout;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
ourView = new GenerateItem(this);
setContentView(ourView);
myLinearLayout = (LinearLayout)findViewById(R.id.linearLayout1);
genButton = new Button(this);
genButton.setText("Generate");
myLinearLayout.addView(genButton);
}
And related XML code from my AndroidManifest:
Code:
<LinearLayout xmlns:android="somelink"
android:id="@+id/linearLayout1"
android:layout_width="wrap_content"
android:layout_height="wrap_content" >
</LinearLayout>
Now I have two questions:
1) Am I going about this problem the correct way using a mix of Design layout tools and code created images (canvas bitmaps)?
2) Can I use canvas bitmaps with an onTouchListener as a button?
Whoaness said:
2) Can I use canvas bitmaps with an onTouchListener as a button?
Click to expand...
Click to collapse
You should use an ImageView instead. Canvas aren't Views, so they aren't managed by the Android System when an event occurs. Canvas are used, for example, to draw anything in a low-level-way (custom views, for example).
I didn't understand the first question..
Sent from my Vodafone 875
Andre1299 said:
You should use an ImageView instead. Canvas aren't Views, so they aren't managed by the Android System when an event occurs. Canvas are used, for example, to draw anything in a low-level-way (custom views, for example).
I didn't understand the first question..
Sent from my Vodafone 875
Click to expand...
Click to collapse
You might have answered my first question. I'm not sure.
I was asking whether I should stick with canvas methods and, from my limited scripting knowledge, draw a hitbox for the onTouch method to detect so I can redraw the object to the fingers position.
I can easily drag imageviews/imagebuttons around. I guess I have to figure out how to create Imageviews, though I think I seen a way to cast bitmaps into an imageview, but it never worked out for me.
Whoaness said:
You might have answered my first question. I'm not sure.
I was asking whether I should stick with canvas methods and, from my limited scripting knowledge, draw a hitbox for the onTouch method to detect so I can redraw the object to the fingers position.
I can easily drag imageviews/imagebuttons around. I guess I have to figure out how to create Imageviews, though I think I seen a way to cast bitmaps into an imageview, but it never worked out for me.
Click to expand...
Click to collapse
Uhm... so, let me know wheter I understood.
In your project you have a button that renders an image (a bitmap) wich is drawn with a canvas. But you want that this image is draggable.
Am I right?
Andre1299 said:
Uhm... so, let me know wheter I understood.
In your project you have a button that renders an image (a bitmap) wich is drawn with a canvas. But you want that this image is draggable.
Am I right?
Click to expand...
Click to collapse
Yes, draggable image button. Although I'm not sure if it needs to be a button, but I thought button properties would be appropriate for touch and dragging.
Sorry for the late reply. I was on a hiatus.