Android – Honeycomb notifications – How to set largeIcon to the right size

androidandroid-3.0-honeycombandroid-notifications

I find myself curious why the setLargeIcon method on Notification.Builder only accepts a Bitmap, with no overload to provide a resource id. Perhaps it was done for performance reasons, but it seems odd as setSmallIcon does accept a res drawable id.

Notification.Builder builder = new Notification.Builder(application);
// ....
builder.setLargeIcon(iconBitmap);  // Requires a Bitmap
builder.setSmallIcon(iconResId);   // Requires a drawable resource ID
Notification notification = builder.getNotification();

Sadly the bitmap provided is not scaled in the notification, so the Bitmap needs to be provided exactly the right size for the notification view.

Assuming I need to provide xhdpi, hdpi, mdpi and ldpi versions of the largeIcon bitmap, what sizes do they need to be? I can see no mention in the docs, or after scouring the wider web.

Best Answer

Not had a chance to check it yet but API 11 introduced the following public dimens:

Should be able to use those to scale your image before setting it on the notification.

Related Solutions

Android – How to close/hide the Android soft keyboard programmatically

You can force Android to hide the virtual keyboard using the InputMethodManager, calling hideSoftInputFromWindow, passing in the token of the window containing your focused view.

// Check if no view has focus:
View view = this.getCurrentFocus();
if (view != null) {  
    InputMethodManager imm = (InputMethodManager)getSystemService(Context.INPUT_METHOD_SERVICE);
    imm.hideSoftInputFromWindow(view.getWindowToken(), 0);
}

This will force the keyboard to be hidden in all situations. In some cases, you will want to pass in InputMethodManager.HIDE_IMPLICIT_ONLY as the second parameter to ensure you only hide the keyboard when the user didn't explicitly force it to appear (by holding down the menu).

Note: If you want to do this in Kotlin, use: context?.getSystemService(Context.INPUT_METHOD_SERVICE) as InputMethodManager

Kotlin Syntax

// Only runs if there is a view that is currently focused
this.currentFocus?.let { view ->
    val imm = getSystemService(Context.INPUT_METHOD_SERVICE) as? InputMethodManager
    imm?.hideSoftInputFromWindow(view.windowToken, 0)
}

Android – How to find out which drawable resource is used

You should be able to get your device's display properties as described here and subsequently determine what resources are being used at runtime by comparing the result against this list:

ldpi: Low-density screens; approximately 120dpi.
mdpi: Medium-densit (on traditional HVGA) screens; approximately 160dpi.
hdpi: High-density screens; approximately 240dpi.
xhdpi: Extra high-density screens; approximately 320dpi. Added in API Level 8
nodpi: This can be used for bitmap resources that you do not want to be scaled to match the device density.
tvdpi: Screens somewhere between mdpi and hdpi; approximately 213dpi. This is not considered a "primary" density group. It is mostly intended for televisions and most apps shouldn't need it—providing mdpi and hdpi resources is sufficient for most apps and the system will scale them as appropriate. This qualifier was introduced with API level 13.

From this information you can deduce the following, which might also be relevant for your question:

There is a 3:4:6:8 scaling ratio between the four primary densities (ignoring the tvdpi density). So, a 9x9 bitmap in ldpi is 12x12 in mdpi, 18x18 in hdpi and 24x24 in xhdpi.

Best Answer

Related Solutions

Android – How to close/hide the Android soft keyboard programmatically

Android – How to find out which drawable resource is used

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