That's a brittle approach for something like this. Android Views are measured by their parent View using the onMeasure method. By providing an initial size to a setImage method to scale to (and especially if you set it based on the display size) you're inviting complexity whenever you want to nest this View within others. Larger screen devices like tablets are a good example of this.
A more idiomatic approach would implement the setImage method of TouchImageView without the width/height parameters at all. Instead it would defer setting the scale and matrices until measurement and implement onMeasure something like this:
protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {
super.onMeasure(widthMeasureSpec, heightMeasureSpec);
if (mNeedsInitialScale) { // Set by setImage when a new image is set
// The measured width and height were set by super.onMeasure above
setInitialScale(getMeasuredWidth(), getMeasuredHeight());
mNeedsInitialScale = false;
}
}
Where the setInitialScale method does everything that the linked setImage method does after the call to super.setImageBitmap. setImage should also set the mNeedsInitialScale field to true.
This way you will never need to worry about the initial size to use, it will be obtained automatically from the View during normal measurement whenever a new image is set.
