I'm developing an application on Android. I need to get the RGB of a particular image at 5 specific points in the image. as shown below:
I am using the following code to capture the RGB of the image:
int color = bitmap.getPixel(x, y);
int red = Color.red(color);
int blue = Color.blue(color);
int green = Color.green(color);
int alpha = Color.alpha(color);
The points defined in the above illustration are just an example!
My question is:
Considering at first that you are using ImageView , one option is to create a variable of type ViewTreeObserver and use the addOnPreDrawListener method to stay "watching and listening" to the specific view as it launches in the application, regardless of device resolution. See:
getMeasuredHeight() : Retrieves height of ImageView
getMeasuredWidth() : Retrieves the length of ImageView
See below:
final ImageView iv = (ImageView)findViewById(R.id.iv);
ViewTreeObserver vto = iv.getViewTreeObserver();
vto.addOnPreDrawListener(new ViewTreeObserver.OnPreDrawListener() {
public boolean onPreDraw() {
iv.getViewTreeObserver().removeOnPreDrawListener(this);
int height = iv.getMeasuredHeight();
int width = iv.getMeasuredWidth();
return true;
}
});
XML
<ImageView
android:id="@+id/iv"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:src="@mipmap/ic_launcher"
/>
No Kotlin using extensions , this is much simpler. See:
iv.viewTreeObserver.addOnPreDrawListener(object : ViewTreeObserver.OnPreDrawListener {
override fun onPreDraw(): Boolean {
iv.viewTreeObserver.removeOnPreDrawListener(this)
val height = iv.measuredHeight
val width = iv.measuredWidth
return true
}
})