how to switch android app theme when an android app run - android

When my android app run, there is a button or something which let customers to select a color to show on primarycolordack, colorprimary and so on. in others words, i want to change app theme. how to do that?

Lucky for you android mead it simple, there is a method for that inside the activity class:
setTheme(android.R.style.MyTheme);
You'll have to call this method inside on create before the super command like this:
public void onCreate(Bundle savedInstanceState) {
setTheme(android.R.style.MyTheme);
super.onCreate(savedInstanceState)
}

Related

Update theme dynamically

I have this app, and I’d like to update the theme dynamically depending on what the user selects. Currently the setTheme() only works when the app loads for the first time. Do you have a strategy or tips you can share on how to set custom theme dynamically? Or alteast how to update the colorPrimaryVariant color dynamically.
override fun onCreate(savedInstanceState: Bundle?) {
setTheme(R.style.Theme_CleanNoteApp_Category) // working fine when the app loads
super.onCreate(savedInstanceState)
}
You can use this approach(line of code) to change the theme during runtime programmatically:
AppCompatDelegate.setDefaultNightMode(AppCompatDelegate.MODE_NIGHT_YES);
You can use something like:
binding.btnChangeTheme.setOnClickListener{
AppCompatDelegate.setDefaultNightMode(AppCompatDelegate.MODE_NIGHT_YES);
}
I found a trick. We can store a reference using SharePref whenever a user selects a theme they want.
Then call recreate() method to restart the Activity lifecycle. On the onCreate just read the reference from the SharedPref set by user and call setTheme(R.style.user_dynamic_theme).

Implementing launch screen for android with Delphi/Firemonkey

reading the https://developer.android.com/topic/performance/vitals/launch-time about the right way to implement a launch screen they say to create a Launcher style
<activity ...
android:theme="#style/AppTheme.Launcher" />
and they say that the easiest way to transition back to your normal theme is to call setTheme(R.style.AppTheme) before calling super.onCreate() and setContentView():
KOTLIN
JAVA
public class MyMainActivity extends AppCompatActivity {
#Override
protected void onCreate(Bundle savedInstanceState) {
// Make sure this is before calling super.onCreate
setTheme(R.style.Theme_MyApp);
super.onCreate(savedInstanceState);
// ...
}
}
problem is with delphi, when/where can I call setTheme(R.style.Theme_MyApp); ? from inside the form create it's not work so seam already too late, and even just after Application.Initialize it's seam to not work either :(

Android AppCompatDelegate.setDefaultNightMode not recreating parent activity in android 9

Hello I am using this AppCompatDelegate to change between day/night themes
I have 2 activities A& B
this code called from activity B
it should recreating activity B & A with the chosen style
here is my code
applyNight.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
if (!isNight) {
SharedPrefrencesMethods.savePreferences(this, getString(R.string.night_key), true);
AppCompatDelegate.setDefaultNightMode(AppCompatDelegate.MODE_NIGHT_YES);
} else {
SharedPrefrencesMethods.savePreferences(this, getString(R.string.night_key), false);
AppCompatDelegate.setDefaultNightMode(AppCompatDelegate.MODE_NIGHT_NO);
}
}
});
I tested it on android 7 & 6 it's working fine i.e when changing mode in activity B and press back activity A recreating with the new theme.
When trying it on android 9 it's changing the activity B only and not affecting it's parent activity A.
I was having that problem too, and then took the advice of Chris Banes in Google's official Android Developers blog https://medium.com/androiddevelopers/appcompat-v23-2-daynight-d10f90c83e94 to set setDefaultNightMode in the app's application class in the first place, so I created a class EcwgApplication extending Application as he shows, and added android:name=".EcwgApplication" in the application section of the manifest. I also put my method for switching themes in the application class as well, that my settings activity can call when the user changes the theme setting (in addition to updating SharedPreferences with the change before calling it), so it looks like this:
public class EcwgApplication extends Application {
public void onCreate() {
super.onCreate();
int selectedDarkLightTheme = PreferenceManager.getDefaultSharedPreferences(this).getInt(getString(R.string.preferences_dark_light_mode_selected_key), AppCompatDelegate.MODE_NIGHT_FOLLOW_SYSTEM);
AppCompatDelegate.setDefaultNightMode(selectedDarkLightTheme);
}
public static void setDarkLightTheme(int selectedDarkLightTheme) {
AppCompatDelegate.setDefaultNightMode(selectedDarkLightTheme);
}
}
This worked fine with Android OS versions 24 through 29, but with 21 (the lowest version this app is supporting) through 23 I would get a black screen on returning to the first activity, and while rotating the screen would fix that, it also made clear that UI state was not being saved. So I changed the StartActivity for the Settings screen to StartActivityForResult, and in onActivityResult, check if the version number <= 23, and if so, do this.recreate().
I need to keep doing more testing, but at least so far everything seems to be working great.

switching between dialog and activity based on device size

In any application the add/edit will be comparatively having lesser inputs. I have seen that the application, esp., calendar, are using clever strategy to show these as simple dialog, so that the user may not notice that there is empty space in the designed form
As shown below
My question is, how to make it happen?
What I'm doing is I extend DialogFragment:
public class AboutFragment extends DialogFragment { ... }
I also have an activity that contains that fragment. And when the dialog/activity needs to be called, this method decides how to display it:
public static void showAbout(Activity parent) {
if (isTablet) {
AboutFragment aboutFragment = AboutFragment.newInstance();
aboutFragment.setStyle(DialogFragment.STYLE_NORMAL, R.style.DialogTheme);
DialogUtils.showDialog(parent, aboutFragment);
} else {
Intent aboutIntent = new Intent(parent, AboutActivity.class);
parent.startActivity(aboutIntent);
}
}
How to decide whether it is a tablet, is totally up to you.
This technique is explained in the documentation.
In my opinion the best approach here is to use
<!-- Theme for a window without an action bar that will be displayed either full-screen
on smaller screens (small, normal) or as a dialog on larger screens
(large, xlarge). -->
"android:Theme.Holo.Light.DialogWhenLarge.NoActionBar"
The best/easiest solution I've found is to always use an Activity, and based on screensize (and version), change your Theme parent.
in res/values/themes.xml
<style name="Detail.Theme" parent="#android:style/Theme.Holo.Light" >
...
</style>
and in res/values-large/themes.xml
<style name="Detail.Theme" parent="#android:style/Theme.Holo.Light.DialogWhenLarge" >
...
</style>
use Context.setTheme method to set them programmetically. As the doc says
this should be called before any views are instantiated in the Context
(for example before calling.
So, to switch between themes need to call setTheme before onCreate
public void onCreate(Bundle savedInstanceState) {
// check screen size
setTheme(dialogTheme);
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_second);
}
As #StinePike answered, setting a dialog theme programatically doesn't do any use (to me), as it shows a wierd black screen behind the dialog, rather than a dimmed background (as shown in the question). This is obviously a bug.
Instead of trying to set it programatically, or in style.xml, and pretty much everywhere except for AndroidManifest.xml, I did the reverse, which has worked for me.
(the solution which I took from the marvelous solution of the above issue)
The simplest solution (that works) as follows:
1. Make the activity a dialog by default through AndroidManifest.xml:
e.g., in the AndroidManifest.xml:
<activity
android:name="com.example.MyActivity"
android:label="#string/title_activity_mine"
android:theme="#android:style/Theme.DeviceDefault.Dialog">
...
</activity>
2. On starting the activity, set the theme to default if device is not a tablet.
if (!(isTablet(this)) {
setTheme(defaultTheme);
}
super.onCreate(savedInstanceState);
...
Note:
solution will work with custom styles defined in style.xml.
Ref:
How to detect device is Android phone or Android tablet?
Dialog with transparent background in Android
Issue 4394 - android - setTheme() does not work as expected
PS: final app on tablet and phone is as follows:
Use a DailogFragment and then control how its shown with setShowsDialog()

Android - How to switch theme on runtime

Could someone tell me how i can switch the the theme from holo to holo light in my application on runtime ?
I would like to have two buttons in settings to choose light or black theme.
How can it be set applicationwide and not only for the activity ?
I already tried a few things with setTheme() but i wasn't able to change the theme when i click a button.
This is my Settings activity where i would like to set the theme:
public class SettingsActivity extends Activity {
#SuppressLint("NewApi")
#Override
protected void onCreate(Bundle savedInstanceState) {
setTheme(android.R.style.Theme_Holo_Light);
super.onCreate(savedInstanceState);
setContentView(R.layout.settings);
}
well this works and my Theme is set but as i am saying i would like to change it systemwide by pressing a button.
Thanks !
As you can see theme is setting on the onCreate() and before setContentView(). So you should call the oncreate() method again when you want to change the theme. But the onCreate() function will be called only once in the life cycle of an Activity.
There is a simple way to do this. I am not sure that it is the best way.
Suppose you want to apply new theme to Activity 1 on a button click.
inside the onClick event
Save the theme to be applied such that it should be retained even after the application restart (preferences or static volatile variables can be used).
Finish the current activity (Activity 1) and call a new activity (Activity 2).
Now in Activity 2
Call Activity 1 and finish current activity (Activity 2).
In Activity 1
Apply the saved theme inside onCreate.
Hope it is not confusing.. :)
You cannot change the theme of other applications (thank goodness).
The only way to somewhat accomplish this would be to create your own build of the operating system with your own theme as the device default theme. However, applications that do not use the device default theme (i.e. they explicitly set the theme to Holo, Holo light, etc) will not get the device default theme.
Edit- To accomplish this application-wide using a base Activity, create an Activity that looks like this:
public class BaseActivity extends Activity {
private static final int DEFAULT_THEME_ID = R.id.my_default_theme;
#Override
public void onCreate(Bundle savedInstanceState) {
int themeId = PreferenceManager.getDefaultSharedPreferences(context)
.getInt("themeId", DEFAULT_THEME_ID);
setTheme(themeId);
super.onCreate(savedInstanceState);
}
}
Then all of your Activities should extend this BaseActivity. When you want to change the theme, be sure to save it to your SharedPreferences.

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