android 自定义ImageView －图片显示相关1

import android.content.Context;

import android.graphics.Canvas;

import android.graphics.Matrix;

import
android.graphics.drawable.BitmapDrawable;

import android.graphics.drawable.Drawable;

import android.net.Uri;

import android.util.AttributeSet;

import
android.util.Log;

import android.widget.ImageView;

import
android.view.ViewTreeObserver;

import
com.tancheng.laikanxing.util.MethodUtils;

/**

 * 根据显示图片的宽高，控件的宽高，决定显示图片的某一个部分，比如， 竖长图上半部分，横长图左半部分

 *

 * @author
Chris Arriola

 */

public class MatrixImageViewextends ImageView {

public TopCropImageView(Contextcontext) {

super(context);

}

public TopCropImageView(Contextcontext, AttributeSetattrs) {

super(context,attrs);

}

public TopCropImageView(Contextcontext, AttributeSetattrs,
int defStyle) {

super(context,attrs,defStyle);

}

@Override

protectedvoid onLayout(booleanchanged,int
left,inttop,intright,

int
bottom) {

super.onLayout(changed,left,top,
right,bottom);

}

@Override

public
void setImageMatrix(Matrix matrix) {

super.setImageMatrix(matrix);

changeMatirx(null);

}

//

@Override

protectedboolean setFrame(intl,intt,intr,intb)
{

boolean
result = super.setFrame(l,t,r,
b);

changeMatirx(null);

returnresult;//super.setFrame(l, t, r, b);

}

@Override

public
void setImageDrawable(Drawable drawable) {

super.setImageDrawable(drawable);

changeMatirx(drawable);

}

@Override

public
void setImageResource(int
resId) {

//
TODO Auto-generated method stub

super.setImageResource(resId);

changeMatirx(getDrawable());

}

@Override

public
void setImageURI(Uri uri) {

//
TODO Auto-generated method stub

super.setImageURI(uri);

changeMatirx(getDrawable());

}

//

privateintdrawableWidth;

privateintdrawableHeight;

private
void changeMatirx(Drawable drawable) {

if (drawable ==null) {

drawable = getDrawable();

if (drawable ==null) {

return;

}

}

drawableWidth =drawable.getIntrinsicWidth();

drawableHeight =drawable.getIntrinsicHeight();

if (drawableWidth <= 0 ||drawableHeight <= 0) {

return;

}

if (drawableHeight >drawableWidth) {

setScaleType(ScaleType.MATRIX);

} else {

setScaleType(ScaleType.CENTER_CROP);

}

}

@Override

public
void setScaleType(ScaleType scaleType) {

changeMatrix(scaleType);

super.setScaleType(scaleType);

}

@Override

protectedvoid onDraw(Canvascanvas) {

super.onDraw(canvas);

}

private
void changeMatrix(ScaleType scaleType) {

if (scaleType == ScaleType.MATRIX) {

final Matrixmatrix = getImageMatrix();

final
int viewWidth = getWidth() - getPaddingLeft()

- getPaddingRight();

final
int viewHeight = getHeight() - getPaddingTop()

- getPaddingBottom();

if (viewHeight <= 0 ||viewWidth <= 0) {

return;

}

float
scale = 0f;

if (drawableWidth *viewHeight
>viewWidth *drawableHeight) {

scale = (float)viewHeight / (float)drawableHeight;

} else {

scale = (float)viewWidth / (float)drawableWidth;

}

scale = (float)viewWidth / (float)drawableWidth;

matrix.setScale(scale,scale);

super.setImageMatrix(matrix);

}

}

}