Android Code Snippet From Drawable to Bitmap

Hello everyone!​

Google Gemini AI gave me these two similar routines to convert a Drawable into a Bitmap, and I'd like to share them with you.

They partly expand on Erel's answer in android.graphics.drawable.Drawable to Bitmap:
https://www.b4x.com/android/forum/threads/android-graphics-drawable-drawable-to-bitmap.10582/

Usage:

' Instantiate the resource loader
    Dim xml As XmlLayoutBuilder
    Dim itemRotate As B4AMenuItem = B4XPages.AddMenuItem(Me, "Rotate")
    itemRotate.AddToBar = True
    itemRotate.Bitmap = DrawableToBitmapPureB4A(xml.GetDrawable("ic_rotate_90_degrees_right_white"))

Before calling DrawableToBitmapPureB4A, Android detects the current device's screen density, selects the appropriate drawable resource from the corresponding resource folder (for example, drawable-xxhdpi), loads it, and automatically scales it if necessary to match the device's actual screen density.

DrawableToBitmapPureB4A VERSION:​

Sub DrawableToBitmapPureB4A(Drawable As Object) As B4XBitmap
    Dim joDrawable As JavaObject = Drawable

    ' If it is already a BitmapDrawable, extract the Bitmap directly.
    Dim className As String = joDrawable.RunMethod("getClass", Null)

    If className.Contains("BitmapDrawable") Then
        Return joDrawable.RunMethod("getBitmap", Null)
    End If

    ' If it is a VectorDrawable, draw it onto an in-memory canvas
    ' Returns the drawable's intrinsic size for the current screen density
    Dim width As Int = joDrawable.RunMethod("getIntrinsicWidth", Null)
    Dim height As Int = joDrawable.RunMethod("getIntrinsicHeight", Null)

    ' The code only uses the default value (100 pixels) as a safety fallback
    ' if the loaded resource is a solid color, which mathematically has no dimensions
    ' (a "borderless color").
    If width <= 0 Then width = 100
    If height <= 0 Then height = 100

    ' Initialize the Android classes required to create the Bitmap.
    Dim joBitmapClass As JavaObject
    joBitmapClass.InitializeStatic("android.graphics.Bitmap")
    Dim configClass As JavaObject
    configClass.InitializeStatic("android.graphics.Bitmap$Config")
    Dim configARGB As Object = configClass.GetField("ARGB_8888")

    ' Create a mutable Bitmap.
    Dim bmp As JavaObject = joBitmapClass.RunMethod("createBitmap", Array(width, height, configARGB))

    ' Create the Android Canvas associated with that Bitmap.
    Dim joCanvas As JavaObject

    joCanvas.InitializeNewInstance("android.graphics.Canvas", Array(bmp))

    ' Draw the Drawable.
    joDrawable.RunMethod("setBounds", Array(0, 0, width, height))
    joDrawable.RunMethod("draw", Array(joCanvas))

    Return bmp
End Sub

---

DrawableToBitmap Java VERSION:​

Example of use:

' Instantiate the resource loader.
Dim xml As XmlLayoutBuilder
Dim drawable As Object = xml.GetDrawable("ic_delete_white_24") ' Returns a Drawable

' Use JavaObject to execute the conversion function.
Dim jo As JavaObject = Me
Dim bmpNative As Object = jo.RunMethod("drawableToBitmap", Array(drawable))

' Assign it to a B4XBitmap (so it can be used with any view or class).
Dim myBitmap As B4XBitmap = bmpNative

#If Java
import android.graphics.Bitmap;
import android.graphics.Canvas;
import android.graphics.drawable.Drawable;
import android.graphics.drawable.BitmapDrawable;

public Bitmap drawableToBitmap(Drawable drawable) {
    if (drawable instanceof BitmapDrawable) {
        return ((BitmapDrawable)drawable).getBitmap();
    }

    // If it is a VectorDrawable (XML) or another drawable type,
    // draw it onto a Bitmap-backed Canvas.
    int width = drawable.getIntrinsicWidth();
    int height = drawable.getIntrinsicHeight();

    // If the drawable has no physical dimensions (for example, a solid color),
    // assign a default base size.
    if (width <= 0) width = 100;
    if (height <= 0) height = 100;

    Bitmap bitmap = Bitmap.createBitmap(width, height, Bitmap.Config.ARGB_8888);
    Canvas canvas = new Canvas(bitmap);
    drawable.setBounds(0, 0, canvas.getWidth(), canvas.getHeight());
    drawable.draw(canvas);

    return bitmap;
}
#End If