// Center as much as possible in one or both axis. Centering is
// defined as follows: if the image is scaled down below the
// view's dimensions then center it (literally). If the image
// is scaled larger than the view and is translated out of view
// then translate it back into view (i.e. eliminate black bars).
protected void center(boolean horizontal, boolean vertical) {
if (mBitmapDisplayed.getBitmap() == null) {
return;
}
Matrix m = getImageViewMatrix();
RectF rect =
new RectF(
0,
0,
mBitmapDisplayed.getBitmap().getWidth(),
mBitmapDisplayed.getBitmap().getHeight());
m.mapRect(rect);
float height = rect.height();
float width = rect.width();
float deltaX = 0, deltaY = 0;
if (vertical) {
int viewHeight = getHeight();
if (height < viewHeight) {
deltaY = (viewHeight - height) / 2 - rect.top;
} else if (rect.top > 0) {
deltaY = -rect.top;
} else if (rect.bottom < viewHeight) {
deltaY = getHeight() - rect.bottom;
}
}
if (horizontal) {
int viewWidth = getWidth();
if (width < viewWidth) {
deltaX = (viewWidth - width) / 2 - rect.left;
} else if (rect.left > 0) {
deltaX = -rect.left;
} else if (rect.right < viewWidth) {
deltaX = viewWidth - rect.right;
}
}
postTranslate(deltaX, deltaY);
setImageMatrix(getImageViewMatrix());
}
protected void postTranslateCenter(float dx, float dy) {
super.postTranslate(dx, dy);
center(true, true);
}
protected void panBy(float dx, float dy) {
postTranslate(dx, dy);
setImageMatrix(getImageViewMatrix());
}