Develop Reference

Android api29 How to automatically add app icon on the home screen at install?

I would like my app to automatically add the launch icon on the home screen at installation.
What I've tried already:
addShortcut method in ActivityMain
private void addShortcut() {
Intent shortcutIntent = new Intent(getApplicationContext(),
MainActivity.class);
shortcutIntent.setAction(Intent.ACTION_MAIN);
Intent addIntent = new Intent();
addIntent
.putExtra(Intent.EXTRA_SHORTCUT_INTENT, shortcutIntent);
addIntent.putExtra(Intent.EXTRA_SHORTCUT_NAME, "HelloWorldShortcut");
addIntent.putExtra(Intent.EXTRA_SHORTCUT_ICON_RESOURCE,
Intent.ShortcutIconResource.fromContext(getApplicationContext(),
R.drawable.ic_launcher_background));
addIntent
.setAction("com.android.launcher.action.INSTALL_SHORTCUT");
addIntent.putExtra("duplicate", false);
getApplicationContext().sendBroadcast(addIntent);
}
AndroidManifest.xml
<uses-permission android:name="com.android.launcher.permission.INSTALL_SHORTCUT" />
Unfortunately, it doesn't work and I think this method is a bit out of date?
Thank You!

It is not possible to run code in direct response to your own app being installed the first time - only once the user opens your app. However, if the user installs your app from Google Play, it will generally add the icon to the home screen by default.

Open the default photo gallery app

I want the gallery app to be launched in a separate window, not in my app. I also dont want to choose a picture, I just want to open the default gallery app.
Some questions are very similiar to this one, but they all open the gallery not as a standalone app, always inside of the app which has called
startActivity(intent);.
see here. This is my app called SM2. inside, the default gallery app is visible, which is not the desired behaviour.
The following code has no use if there is no package named 'com.android.gallery' on the phone:
Intent launchIntent = getPackageManager().getLaunchIntentForPackage("com.android.gallery");
if (launchIntent != null) {
startActivity(launchIntent);//null pointer check in case package name was not found
}
this opens a gallery in my app, not as wished as a standalone task:
Intent intent1 = new Intent(Intent.ACTION_VIEW, Uri.parse(Environment.getExternalStoragePublicDirectory(
Environment.DIRECTORY_MOVIES)));
startActivity(intent1);
and this does also open the gallery in my app:
Intent intent = new Intent(Intent.ACTION_VIEW, Uri.parse(
"content://media/internal/images/media/"));
startActivity(intent);

It is launched inside of the application
It is being launched in your task. You can use FLAG_ACTIVITY_NEW_TASK on your Intent to have it launch in its own task.
I also dont want to choose a picture, I just want to open the default gallery app
You are welcome to try using CATEGORY_APP_GALLERY, though not all gallery apps might have an activity that supports this.

Java - How to pick multiple files in Android

I’m doing an application for Android (version 4.4), and I’m trying to select multiple files (.doc, .pdf) at the same time. The objective is to navigate through directories, select some desiderated files and return a list of these files.
I’ve initially tried in this way, but the instruction Extra_Allow_Multiple doesn’t work: I can only select one file at a time.
Intent intent = new Intent("com.sec.android.app.myfiles.PICK_DATA");
intent.putExtra("CONTENT_TYPE", "*/*");
intent.putExtra(Intent.EXTRA_ALLOW_MULTIPLE, true);
intent.addCategory(Intent.CATEGORY_DEFAULT);
startActivityForResult(intent, PICKFILE_REQUEST_CODE);
So I’ve tried in this other way, but I’m not browsing in all directories of the device, only in specific ones (images/videos/audio…), and I can’t select
multiple files for the same reason as before.
Intent intent = new Intent();
intent.setType("*/*");
intent.putExtra(Intent.EXTRA_ALLOW_MULTIPLE, true);
intent.setAction(Intent.ACTION_GET_CONTENT);
startActivityForResult(intent, PICKFILE_REQUEST_CODE);
I’ve tried also other combinations, but often an error similar to this appears:
android.content.ActivityNotFoundException: No Activity found to handle Intent { act=android.intent.action.GET_CONTENT (has extras) }
How can I select multiple files, possibly in a way alike to first method?

Have you tried this?
Intent intent = new Intent(Intent.ACTION_GET_CONTENT);
intent.setType("file/*");
startActivityForResult(intent, PICKFILE_REQUEST_CODE);
I took this snippet of code from this StackOverflow question.
I am not very familiar with this functionality in Android, but you can apparently retrieve the files Uri with onActivityResult() if this helps any further.

getting installed applications programmatically

I am trying to get the installed application in Android after clicking a icon. Under the icon click code I wrote following code:
Intent intent = new Intent(Intent.ACTION_MAIN);
intent.addCategory(Intent.ACTION_ALL_APPS);
startActivity(intent);
But it kills the application. I want to show the installed applications on the screen programmatically like when we see when press app key on Android.
Is it possible?
where am I doing wrong?

To get list of all installed application you can use the following code
Intent mainIntent = new Intent(Intent.ACTION_MAIN, null);
mainIntent.addCategory(Intent.CATEGORY_LAUNCHER);
List pkgAppsList = getPackageManager().queryIntentActivities( mainIntent, 0);

Debugging Intents

I asked a question previously about what shows up in the IntentChooser when I send an Intent with ACTION_SEND and MIME type "image/png". The problem is that some phones come with a default messaging app that is not showing up in the list, mine included (myTouch 4G) as well as a user that I speak with over email (using an HTC EVO). If I choose a Send or Share option from the built in gallery app or another application on the same image I'm saving and attempting to send directly from my app, Messages shows up in the list. From my app it does not. Other phones don't have this problem, so it's clearly a platform specific thing. But that doesn't mean I should just ignore the problem.
So, I go to troubleshooting the issue. I register one of the activities in my app to receive the the same type of intent, and then hit a breakpoint to analyze the Intent object being sent from the two different ways of sending it.
The problem is, the intent I'm sending and the intent being sent from Gallery or AndroZip (where Messages does show up in the chooser) seem to be the same. They both have the same action, same categories, same flags, same mime type. What else can I inspect on the Intent from Gallery or AndroZip to tell if there's some more information I can add to my Intent to get the default messaging app to show up in the chooser in cases where it is not?

The problem is specific to HTC Sense phones, and it arises because their Gallery and Messaging apps are different to the stock ones.
Specifically the Intent sent from Gallery to Messaging has the action android.intent.action.SEND_MSG which is different to android.intent.action.SEND. The Sense messaging app doesn't handle SEND, unlike the stock messaging app.
So the question becomes, how is the Sense Gallery app creating an activity chooser dialog which combines both SEND and SEND_MSG ?
I've done some research and got mostway there... the code below works, but the "Messages" entry in the dialog appears at the top rather than in alphabetical order as per Gallery. Doubtless some more research into intents would correct that, but at least this works:
// Create a chooser for things that can ACTION_SEND images
Intent intent = new Intent(Intent.ACTION_SEND);
Uri data = Uri.parse("content://media/external/images/media/98");
intent.putExtra(Intent.EXTRA_STREAM, data);
intent.setType("image/jpeg");
Intent chooser = Intent.createChooser(intent, "Blah");
// Add the stupid HTC-Sense-specific secondary intent
Intent htcIntent = new Intent("android.intent.action.SEND_MSG");
htcIntent.putExtra(Intent.EXTRA_STREAM, data);
htcIntent.setType("image/jpeg");
chooser.putExtra(Intent.EXTRA_INITIAL_INTENTS, new Intent[] { htcIntent });
// Show the chooser
startActivity(chooser);

First of all, +1 to Reuben, he is the genius, not me. But I had to modify his code a bit to get it to work. Basically I had to putExtra() on the htcIntent or the image never got stuck to the Intent.
Tested and validated on a Droid X and HTC Incredible (which had the same problem until now thanks to Reuben).
Uri uri = Uri.fromFile(new File(mFile));
Intent intent = new Intent(Intent.ACTION_SEND);
intent.putExtra(Intent.EXTRA_STREAM, uri);
intent.setType("image/png");
Intent htcIntent = new Intent("android.intent.action.SEND_MSG");
htcIntent.setType("image/png");
htcIntent.putExtra(Intent.EXTRA_STREAM, uri);
Intent chooser = Intent.createChooser(intent, "Send Method");
chooser.putExtra(Intent.EXTRA_INITIAL_INTENTS, new Intent[] { htcIntent });
startActivity(chooser);
Edit: I realize I'm putting the image on two Intents now, but I couldn't get it to work any other way.

Instead of debugging the intents, why not try to compare how your starting the chooser with how the gallery is doing it. It is open source after all, so instead of trying to guess at the issue with the result, you can debug from the cause.
https://android.googlesource.com/platform/packages/apps/Gallery3D