Database Users

event handling in dynamically created control

Hi all,
I am using eVC++ 4.0, and i've dynamically created a CListView like this:
Code:
lv.Create(0,_T(""),WS_CHILD|WS_VISIBLE,r,this,5);
but I dont know how to handle the events of this control... any ideas??
Mohammad

To get events from a listview (win32) I normally subclass it. I use the subclassing routine to post a message back to the parent when the user is doing something like tapping on it, then the windows routine can check whats selected etc and act on it. Is subclassing possible in mfc ?( I don't use it).

Thank u
but can anybody post some code??
thnx

Ok, I am a bit lazy to look up code at the moment, but here's something:
Yes, subclassing is possible in MFC. You just derive your class from the basic class provided like this:
Code:
class MyListView : pubic CListView
Then you add message handlers in the normal matter.
EDIT: The following passage is incorrect:
But I think subclassing may not be necessary in you case. List box controls send WM_COMMAND messages with notifications of major events like selection change to the parent window. All you have to do is to create a WM_COMMAND handler in your parent class.
Sorry I was thinking of ListBox not list view when I wrote it.
To manually add message handlers you need to put macros like ON_MESAGE or ON_COMMAND in the DECLARE_MESSAGE_MAP section of the class cpp file. All the detaisl are available on MSDN.

Are you saying that a listview will send the same WM_COMMAND as a list box in mfc? Dose this also happen in win32 made listviews. I have always thought it was a bit too tedious to find out when the user taps an item in the listview.
After reading your post levenum I had a quick look and it says that a WM_NOTIFY gets sent to the parent with a LVN_ITEMCHANGED for example. I had not used the LVN_**** because when I looked at them there was none that seem to deal with selections. I would guess that LVN_ITEMACTIVATE or LVN_ODSTATECHANGED would be usefull for this but then a second tap would not be picked up still leaving me wanting subclassing in many situations to get the users tap.

Ok, I have read what u wrote guys and my problem is almost solved, I used the OnNotify() method to handle messages sent from child controls like this:
Code:
BOOL CTest2Dlg::OnNotify(WPARAM wParam, LPARAM lParam, LRESULT* pResult)
{
// TODO: Add your specialized code here and/or call the base class
if(wParam ==5 ) //5 is control ID
{
NMHDR *ph =(NMHDR*)lParam;
if(ph->code==NM_CLICK)
MessageBox("Click");
else if(ph->code==HDN_ITEMCLICK)
MessageBox("Item Click");
else
{
CString str;
str.Format("%d",ph->code);
MessageBox(str);
}
}
return CDialog::OnNotify(wParam, lParam, pResult);
}
Now there still a very small prolem: what messages should I handle for 'Selected Item Changed' event ?? I know its easy but I couldnt find it
Regards

mohgdeisat: I am sorry, I made a mistake about WM_COMMAND.
OdeeanRDeathshead is right, I was thinking of a list box not list view.
To make up for this, here is some sample code from a win32 dialog app that uses list view control. I hope it will be of some help:
Code:
//this is from the dialog window function:
case WM_NOTIFY: //handle events:
nmhdr = (LPNMHDR)lParam;
switch (nmhdr->idFrom)
{
case IDC_LEDLIST: //list control ID.
return OnLEDListEvent(hwndDlg, (LPNMLISTVIEW)lParam);
break;
}
break;
BOOL OnLEDListEvent(HWND hwndDlg, LPNMLISTVIEW nmlv)
{
/////
// Handles list view control notification messages
switch (nmlv->hdr.code)
{
case LVN_ITEMCHANGED:
return OnLEDListItemChanged(hwndDlg, nmlv);
break;
}
return 0;
}
BOOL OnLEDListItemChanged(HWND hwndDlg, LPNMLISTVIEW nmlv)
{
if (ListView_GetSelectionMark(nmlv->hdr.hwndFrom) != nmlv->iItem) return 0;
/* do what you need here */
return 0;
}
Don't mind the fact that I used 3 different functions. This is part of a bigger program and I am trying to keep things well organized without resorting to classes.
As I understand it, LVN_ITEMCHANGE is received for different reasons so I try to handle only the one coming from selected item. LVN_ITEMACTIVATE is only sent when you double click the item so if you just want to catch selection change you need to use LVN_ITEMCHANGE.
Once again, sorry for confusing you before.

thanx pals, good job!!!
I think my problem is now solved with ur help :wink:
Mohammad

Ok guys, I said that my problem was solved, yet, another problem arises...
When the list view is in the report mode, how can I determine when a header button is clicked, and determine which one was clicked???????
thanx in advance

To identify a header column click, you need to handle the WM_NOTIFY/HDN_ITEMCLICK message. Normally this message will be received by the header's parent control (i.e. the listview) -- some frameworks may redirect the message to the header control itself. I haven't worked with MFC in 10 years so I can't really if it reflects notification messages back to the control.
If you're trying to implement column sort, do yourself a favor and check out the Windows Template Library (WTL) at sourceforge.net. It's a set of C++ template classes that provide a thin yet useful wrapper around the standard Windows UI components. One of the classes is a sortable listview control. I've been using WTL with big Windows for more than 5 years -- you couldn't pay me to go back to MFC.

hi,
I have seen the WTL library and it seems very useful and time-saver, but I have a couple of questions about it:
1. can WTL 8.0 be installed with VC++ 6.0, specifically the appwizard stuff??how?? I see only javascript files of vc7.0 and 7.1 and 8.0!!
2. is there a good documentation about those classes??
Mohammad

I don't know about WTL 8; I'm still using WTL 7.5 with VS .Net 2003 for all my Win32 development. My guess is that it wouldn't work too well, as WTL is based on ATL, which has substantially changed between VC 6 and 7.
Good references for WTL include www.codeproject.com/wtl, and the WTL group over at Yahoo groups (reflected at www.gmane.org).

[Q] app crashes whenever call is made to change the content viewthe

whenever I use
Code:
tv.setText("Game Over!"); setContentView(tv);
my program crashes (note: tv is an object of the TextView class)
Before this call is made the program is set to a default view that contains a text view, buttons, etc. But the crash only happens when I call the method to change the view. Any ideas?

You probably wouldnt wanna do setContentView on a textview, unless its the only thing you want on the screen. Are you creating the textview dynamically? (In the java code) Or is this a textview you create in the xml. If you are doing it dynamically, are you giving it LayoutParams first?

Yes its dynamic. What kind of LayoutParams do you mean?
Sent from my GT-I9000M using XDA App

If you just create a new textview...
TextView text = new TextView(context);
its just floating around not attached to anything. Just create a quick layout with a textview in it, and do
setContentView(R.layout.layout2);

or you could try
tv.setLayoutParams(new LayoutParams(LayoutParam.WRAP_CONTENT,LayoutParam.WRAP_CONTENT));

It still crashes, no matter what I do as soon as I try to do anything with the TextView tv, it crashes
setting it works: final TextView tv = (TextView) findViewById(R.id.stats);
But doing ANYTHING with tv crashes.
Examples:
tv.setLayoutParams(new LayoutParams(LayoutParams.WRAP_CONTENT,LayoutParams. WRAP_CONTENT));
tv.setText("testing");
Anything I'm overlooking?

Well for starters you cant change anything about a variable that you declare as final..

Image Low Quality

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.

Adding Bookmarks Are Invisible?

So, I wrote this block of code:
Code:
ContentValues values = new ContentValues();
values.put(BookmarkColumns.BOOKMARK, "1");
values.put(BookmarkColumns.CREATED, "1311170108");
values.put(BookmarkColumns.DATE, "1311170708");
values.put(BookmarkColumns.FAVICON, "favicon");
values.put(BookmarkColumns.TITLE, "XDA");
values.put(BookmarkColumns.URL, "http://forum.xda-developers.com");
values.put(BookmarkColumns.VISITS, "1");
getContentResolver().insert(Browser.BOOKMARKS_URI, values);
When executed, I get no errors. Looking in the browser bookmarks section, the book mark is not there. If i click the Most Visited tab, this shows up and also has the yellow bookmark star next to it, indicating that it is a bookmark. If i click the star to unbook mark it, and click it again, then view the Bookmarks tab, it shows up.
If I use another piece of code to print out all the bookmarks found after I add it, mine shows up
Even with rebooting, they are not showing.
So I ask, why is it that they are not showing up in the bookmarks page of the browser?
I have tried everything and looked around everywhere, and nothing
Thanks!

there is no sanctioned way of adding a bookmark without user input. the normal way would be a call to android.provider.Browser.saveBookmark()
Code:
public static final void saveBookmark(Context c, String title, String url) {
Intent i = new Intent(Intent.ACTION_INSERT, Browser.BOOKMARKS_URI);
i.putExtra("title", title);
i.putExtra("url", url);
c.startActivity(i);
}
other than that dealing with the DB directly would be the only way to add one. try to follow that startActivity to the dialog and see if there is an intent sent to the Browser telling it the DB was updated

killersnowman said:
there is no sanctioned way of adding a bookmark without user input. the normal way would be a call to android.provider.Browser.saveBookmark()
Code:
public static final void saveBookmark(Context c, String title, String url) {
Intent i = new Intent(Intent.ACTION_INSERT, Browser.BOOKMARKS_URI);
i.putExtra("title", title);
i.putExtra("url", url);
c.startActivity(i);
}
other than that dealing with the DB directly would be the only way to add one. try to follow that startActivity to the dialog and see if there is an intent sent to the Browser telling it the DB was updated
Click to expand...
Click to collapse
But, even with restarting the device the book marks are not there. Surely the browser updates the database at that point.
But it also dosnt make sense because if the page was shown in the history, it has the bookmarked indicator next to it
I must do all of this in a fully transparent way. Showing that popup for each one will not do :/

there are a few other columns that are interesting. 'user_entered' which can be '0' or '1'
But I think your best bet is to find the dialog that saveBookmark() calls and analyze its src

Here it is addBookmark()
http://www.java2s.com/Open-Source/A...rowser/com/android/browser/Bookmarks.java.htm
It appears to be static. Why not just call this method?
static void addBookmark(Context context, ContentResolver cr, String url, String name, Bitmap thumbnail, boolean retainIcon)
------nvm i think its package restricted
From something awesome

[Library] StoreBox, an open-source Android library for streamlining SharedPreferences

When getting a value from any preferences, whether private Activity or default shared preferences, you would normally have to get a reference to a SharedPreferences instance, for example using
Code:
SharedPreferences prefs = PreferenceManager.getDefaultSharedPreferences(someContext);
Only after that we can start getting/saving the values, such as
Code:
String username = prefs.getString("username", "");
prefs.edit().putString("username", "androiduser").apply();
This can get tedious if the values need to be saved and retrieved from multiple places as the caller is always required to supply the key of the preference, know under what type it is saved, and know what default should be used. This can also become error prone as more keys get used. Putting commonly accessed preferences behind a wrapper is a reasonable solution, but still requires some boilerplate code.
What if however we could define an interface like
Code:
public interface MyPreferences {
@KeyByString("username")
String getUsername();
@KeyByString("username")
void setUsername(String value);
}
for everyone to use in order to save and get values? The caller doesn't need to worry about the key, neither needs to think about what type the key should use, and the process of retrieving/saving is hidden behind a method name with improved semantics.
With StoreBox that becomes reality. Given the above interface definition you can easily create an instance of the interface using
Code:
MyPreferences prefs = StoreBox.create(context, MyPreferences.class);
and you will be able to retrieve/save the value just by calling the defined methods
Code:
String username = prefs.getUsername();
prefs.setUsername("androiduser");
You can read more about the project here, including details on how it can be used and added to a project.
Let me know what you think and whether you find it useful. Thanks!

great! ty

Great work!