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@gelitenight
Created December 17, 2013 03:53
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This view will auto determine the width or height by determining if the height or width is set(exact size or match_parent) and scale the other dimension depending on the images dimension This view also contains an ImageChangeListener which calls changed(boolean isEmpty) once a change has been made to the ImageView @author Maurycy Wojtowicz
package com.feizan.android.snowball.ui.imageview;
import android.content.Context;
import android.graphics.Bitmap;
import android.graphics.drawable.Drawable;
import android.util.AttributeSet;
import android.widget.ImageView;
import android.widget.RelativeLayout;
/**
* This view will auto determine the width or height by determining if the
* height or width is set and scale the other dimension depending on the images dimension
* <p/>
* This view also contains an ImageChangeListener which calls changed(boolean isEmpty) once a
* change has been made to the ImageView
*
* @author Maurycy Wojtowicz
*/
public class ScaleImageView extends ImageView {
private ImageChangeListener imageChangeListener;
private boolean scaleToWidth = false; // this flag determines if should measure height manually dependent of width
public ScaleImageView(Context context) {
super(context);
init();
}
public ScaleImageView(Context context, AttributeSet attrs, int defStyle) {
super(context, attrs, defStyle);
init();
}
public ScaleImageView(Context context, AttributeSet attrs) {
super(context, attrs);
init();
}
private void init() {
this.setScaleType(ScaleType.CENTER_INSIDE);
}
@Override
public void setImageBitmap(Bitmap bm) {
super.setImageBitmap(bm);
if (imageChangeListener != null)
imageChangeListener.changed((bm == null));
}
@Override
public void setImageDrawable(Drawable d) {
super.setImageDrawable(d);
if (imageChangeListener != null)
imageChangeListener.changed((d == null));
}
@Override
public void setImageResource(int id) {
super.setImageResource(id);
}
public interface ImageChangeListener {
// a callback for when a change has been made to this imageView
void changed(boolean isEmpty);
}
public ImageChangeListener getImageChangeListener() {
return imageChangeListener;
}
public void setImageChangeListener(ImageChangeListener imageChangeListener) {
this.imageChangeListener = imageChangeListener;
}
@Override
protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {
int widthMode = MeasureSpec.getMode(widthMeasureSpec);
int heightMode = MeasureSpec.getMode(heightMeasureSpec);
int width = MeasureSpec.getSize(widthMeasureSpec);
int height = MeasureSpec.getSize(heightMeasureSpec);
/**
* if both width and height are set scale width first. modify in future if necessary
*/
if (widthMode == MeasureSpec.EXACTLY || widthMode == MeasureSpec.AT_MOST) {
scaleToWidth = true;
} else if (heightMode == MeasureSpec.EXACTLY || heightMode == MeasureSpec.AT_MOST) {
scaleToWidth = false;
} else
throw new IllegalStateException("width or height needs to be set to match_parent or a specific dimension");
if (getDrawable() == null || getDrawable().getIntrinsicWidth() == 0) {
// nothing to measure
super.onMeasure(widthMeasureSpec, heightMeasureSpec);
return;
} else {
if (scaleToWidth) {
int iw = this.getDrawable().getIntrinsicWidth();
int ih = this.getDrawable().getIntrinsicHeight();
int heightC = width * ih / iw;
if (height > 0)
if (heightC > height) {
// dont let hegiht be greater then set max
heightC = height;
width = heightC * iw / ih;
}
this.setScaleType(ScaleType.CENTER_CROP);
setMeasuredDimension(width, heightC);
} else {
// need to scale to height instead
int marg = 0;
if (getParent() != null) {
if (getParent().getParent() != null) {
marg += ((RelativeLayout) getParent().getParent()).getPaddingTop();
marg += ((RelativeLayout) getParent().getParent()).getPaddingBottom();
}
}
int iw = this.getDrawable().getIntrinsicWidth();
int ih = this.getDrawable().getIntrinsicHeight();
width = height * iw / ih;
height -= marg;
setMeasuredDimension(width, height);
}
}
}
}
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