Why do activities have their own Icon? - android

Is there a specifici reason why if I have MainActivity, it has it's own Icon, yet if I create SecondActivity it has a separate icon? If I download an app from the Play store it's all from one icon. Am I just being dumb? Or is there a specific reason why this is. Thanks so much!

Any activity that declares the following intent filter will have an icon in the system's app listing:
<intent-filter>
<action android:name="android.intent.action.MAIN" />
<category android:name="android.intent.category.LAUNCHER" />
</intent-filter>
If you only want one icon then only put this intent filter inside your main activity.

Each activity can be launched independently - and thereby can have its own icon - in the Launcher. Also, I think in later APIs, the icon can be displayed inside the Activity itself.

Related

Google Docs main activity: couldn't find address

I am developing a Huawei custom Theme. I was trying to change some Google apps (Documents, Sheets and Slides) icons. So I used as address their package name e.g. com.google.android.apps.docs.editors.slides
Since it didn't work, I tried with some activities, found in the manifest file, but no one worked yet. (for example com.google.android.apps.editors.homescreen.HomescreenActivity, which is the first one that appears when I open Slides);
So the question is:
is there a way to identify which is the main activity, nay, which is the activity who defines app icon?
Usually, the main activity declares the following intent filters (documentation) in order to indicate for the system that this activity is Main and is a launcher activity:
<activity android:name=".ActivityClassName">
<intent-filter>
<action android:name="android.intent.action.MAIN" />
<category android:name="android.intent.category.LAUNCHER" />
</intent-filter>
</activity>

BroadcastReceiver instead of Activity

I have an application that doesn't have any activities. All it does is show a notification. Is it possible to put launcher filter on the BroadcastReceiver instead of the main activity?
Here is what I've tried:
<receiver android:name=".LaunchReceiver">
<intent-filter>
<action android:name="android.intent.action.MAIN" />
<category android:name="android.intent.category.LAUNCHER" />
</intent-filter>
</receiver>
It doesn't work. The app installs, but there is no icon in the launcher.
If it's not possible, are there any other ways to not show the activity? Currently I just have an empty activity and call finish() from onCreate(), but the it still shows up for a split second, which doesn't look nice.
A Receiver receives broadcasts only. Only an activity belongs in the launcher. Intents and filters explains much of this.
To make an invisible activity (to not see it while you quickly finish() it) declare it with this theme:
#android:style/Theme.Translucent.NoTitleBar
But you better also add the following if you have an invisible activity (to avoid confusing the user):
android:noHistory="true"

How to create additional launcher Icon(s) for same android app?

I have an application where I need to provide a additional icon acccessible in applications to launch an activity from the same application.
So that when application installs it shows two icons in the applications list, one icon to launch the app is already there, how to have the other icon and then how can I start the required activity from that icon/shortcut.
add this in the manifest file inside the activity tag which you want to show in the launcher
<intent-filter>
<action android:name="android.intent.action.MAIN" />
<category android:name="android.intent.category.LAUNCHER" />
</intent-filter>

Android Manifest

I found a code on internet for displaying a splash screen before starting an android application. He made some changes in the code which he didn't explain well.
He used Launcher for Splash screen Activity and used Default in main android Activity.
He used Package name with main class name instead of pre-generated code for android:name in action.
Here is the code.
<category android:name="android.intent.category.LAUNCHER" />
</intent-filter>
</activity>
<activity
android:name=".StartingPoint"
android:label="#string/title_activity_starting_point" >
<intent-filter>
<action android:name="com.alfred.splashscreenwithsound.STARTINGPOINT" />
<category android:name="android.intent.category.DEFAULT" />
</intent-filter>
</activity>
So my question
What is the difference between LAUNCHER & DEFAULT.
Is there any good behind changing the android:name in action to the package name.
when you write LAUNCHER it will launch application with Icon and if you remove it it will not show you the application Icon
"android.intent.category.LAUNCHER" serves as our main entry into the app.
android.intent.category.DEFAULT be set if the Activity should be an option for the default action (center press) to perform on a piece of data.
Refer this
LAUNCHER is your main page DEFAULT is your Activity page when load the app. on device first LAUNCHER will open. Then If you trigger your activity page DEFAULT will open.

How can I create a "Launcher" Activity programmatically?

Instead of declaring a pre-determined launcher activity in my manifest using an intent filter:
<intent-filter>
<action android:name="android.intent.action.MAIN" />
<category android:name="android.intent.category.LAUNCHER" />
</intent-filter>
Could I, instead, be given programmatic control over the activity which gets run when the application launches?
I'm not able to find anywhere in the documentation which says I must use the intent filter approach... but I also don't see any discussion of the alternative(s).
http://developer.android.com/guide/topics/fundamentals/activities.html
http://developer.android.com/guide/topics/intents/intents-filters.html
Thanks.
As far as I know, it's not possible. Android creates or sets up the hard link of the App icons to their respective activities by looking at the manifest. If you don't set it, you will not find any icons/shortcuts for your app after you install it.

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