android.widget.ImageView#measure ( )源码实例Demo

/**
 * Creates a View using the bitmap copy of <code>view</code>. If <code>view</code> is large,
 * the copy will use a scaled bitmap of the given view.
 *
 * @param sceneRoot The ViewGroup in which the view copy will be displayed.
 * @param view The view to create a copy of.
 * @param parent The parent of view.
 */
public static View copyViewImage(ViewGroup sceneRoot, View view, View parent) {
    Matrix matrix = new Matrix();
    matrix.setTranslate(-parent.getScrollX(), -parent.getScrollY());
    view.transformMatrixToGlobal(matrix);
    sceneRoot.transformMatrixToLocal(matrix);
    RectF bounds = new RectF(0, 0, view.getWidth(), view.getHeight());
    matrix.mapRect(bounds);
    int left = Math.round(bounds.left);
    int top = Math.round(bounds.top);
    int right = Math.round(bounds.right);
    int bottom = Math.round(bounds.bottom);

    ImageView copy = new ImageView(view.getContext());
    copy.setScaleType(ImageView.ScaleType.CENTER_CROP);
    Bitmap bitmap = createViewBitmap(view, matrix, bounds, sceneRoot);
    if (bitmap != null) {
        copy.setImageBitmap(bitmap);
    }
    int widthSpec = View.MeasureSpec.makeMeasureSpec(right - left, View.MeasureSpec.EXACTLY);
    int heightSpec = View.MeasureSpec.makeMeasureSpec(bottom - top, View.MeasureSpec.EXACTLY);
    copy.measure(widthSpec, heightSpec);
    copy.layout(left, top, right, bottom);
    return copy;
}
 

@Override
protected void onCreate(@Nullable Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    LinearLayout contentView = new LinearLayout(this);
    ImageView imageView0 = new ImageView(this);
    imageView0.setImageBitmap(ShadowBitmapFactory.create("AndroidGodEye-Bitmap", null, new Point(200, 100)));
    ImageView imageView1 = new ImageView(this);
    imageView1.setImageBitmap(ShadowBitmapFactory.create("AndroidGodEye-Bitmap", null, new Point(200, 100)));
    ImageView imageView2 = new ImageView(this);
    imageView2.setImageBitmap(ShadowBitmapFactory.create("AndroidGodEye-Bitmap", null, new Point(200, 100)));
    imageView3 = new ImageView(this);
    imageView3.setImageBitmap(ShadowBitmapFactory.create("AndroidGodEye-Bitmap", null, new Point(200, 100)));
    contentView.addView(imageView0);
    contentView.addView(imageView1);
    contentView.addView(imageView2);
    contentView.addView(imageView3);
    setContentView(contentView);
    imageView0.measure(50, 50);
    imageView0.layout(0, 0, 50, 50);
    imageView1.measure(500, 500);
    imageView1.layout(0, 0, 500, 500);
    imageView2.measure(210, 95);
    imageView2.layout(0, 0, 210, 95);
    imageView3.measure(50, 50);
    imageView3.layout(0, 0, 50, 50);
}
 

/**
 * Creates a View using the bitmap copy of <code>view</code>. If <code>view</code> is large,
 * the copy will use a scaled bitmap of the given view.
 *
 * @param sceneRoot The ViewGroup in which the view copy will be displayed.
 * @param view The view to create a copy of.
 * @param parent The parent of view
 */
@NonNull
public static View copyViewImage(@NonNull ViewGroup sceneRoot, @NonNull View view, @NonNull View parent) {
    Matrix matrix = new Matrix();
    matrix.setTranslate(-parent.getScrollX(), -parent.getScrollY());
    ViewUtils.transformMatrixToGlobal(view, matrix);
    ViewUtils.transformMatrixToLocal(sceneRoot, matrix);
    RectF bounds = new RectF(0, 0, view.getWidth(), view.getHeight());
    matrix.mapRect(bounds);
    int left = Math.round(bounds.left);
    int top = Math.round(bounds.top);
    int right = Math.round(bounds.right);
    int bottom = Math.round(bounds.bottom);

    ImageView copy = new ImageView(view.getContext());
    copy.setScaleType(ImageView.ScaleType.CENTER_CROP);
    Bitmap bitmap = createViewBitmap(view, matrix, bounds);
    if (bitmap != null) {
        copy.setImageBitmap(bitmap);
    }
    int widthSpec = View.MeasureSpec.makeMeasureSpec(right - left, View.MeasureSpec.EXACTLY);
    int heightSpec = View.MeasureSpec.makeMeasureSpec(bottom - top, View.MeasureSpec.EXACTLY);
    copy.measure(widthSpec, heightSpec);
    copy.layout(left, top, right, bottom);
    return copy;
}
 

protected void workGetImage(ImageView imageView) {
    imageView.setDrawingCacheEnabled(true);
    imageView.measure(View.MeasureSpec.makeMeasureSpec(0, View.MeasureSpec.UNSPECIFIED), View.MeasureSpec.makeMeasureSpec(0, View.MeasureSpec.UNSPECIFIED));
    imageView.layout(0, 0, imageView.getMeasuredWidth(), imageView.getMeasuredHeight());
    imageView.buildDrawingCache(true);
    output_bitmap = Bitmap.createBitmap(imageView.getDrawingCache());
    imageView.setDrawingCacheEnabled(false);
}
 

@Override
protected void onFinishInflate() {
    super.onFinishInflate();
    mScrollView = (ScrollView) findViewById(R.id.scroll_view);
    mContent = (CellLayout) findViewById(R.id.folder_content);
    int measureSpec = MeasureSpec.UNSPECIFIED;

    LauncherAppState app = LauncherAppState.getInstance();
    DeviceProfile grid = app.getDynamicGrid().getDeviceProfile();

    mContent.setCellDimensions(grid.folderCellWidthPx, grid.folderCellHeightPx);
    mContent.setGridSize(0, 0);
    mContent.getShortcutsAndWidgets().setMotionEventSplittingEnabled(false);
    mContent.setInvertIfRtl(true);
    mFolderName = (FolderEditText) findViewById(R.id.folder_name);
    mFolderName.setFolder(this);
    mFolderName.setOnFocusChangeListener(this);

    // We find out how tall the text view wants to be (it is set to wrap_content), so that
    // we can allocate the appropriate amount of space for it.
    mFolderName.measure(measureSpec, measureSpec);
    mFolderNameHeight = mFolderName.getMeasuredHeight();

    // We disable action mode for now since it messes up the view on phones
    mFolderName.setCustomSelectionActionModeCallback(mActionModeCallback);
    mFolderName.setOnEditorActionListener(this);
    mFolderName.setSelectAllOnFocus(true);
    mFolderName.setInputType(mFolderName.getInputType() |
            InputType.TYPE_TEXT_FLAG_NO_SUGGESTIONS | InputType.TYPE_TEXT_FLAG_CAP_WORDS);
    mAutoScrollHelper = new FolderAutoScrollHelper(mScrollView);

    if (SettingsProvider.getBoolean(mLauncher,
            SettingsProvider.SETTINGS_UI_HOMESCREEN_HIDE_ICON_LABELS,
            R.bool.preferences_interface_homescreen_hide_icon_labels_default)) {
        mFolderName.setVisibility(View.GONE);
        mFolderNameHeight = getPaddingBottom();
    }

    mFolderLock = (ImageView) findViewById(R.id.folder_lock);
    mFolderTitleSection = (RelativeLayout) findViewById(R.id.folder_title_section);
    mFolderLock.measure(measureSpec, measureSpec);
    mFolderLock.setOnClickListener(this);
    mFolderTitleSection.measure(measureSpec, measureSpec);
}
 

private void createRoundedBitmap()
{
	if (mBitmap == null)
		return;
	
    int targetWidth = getWidth();
    int targetHeight = getHeight();
    if (targetWidth == 0 || targetHeight == 0)
    	return;
    
    Bitmap targetBitmap = Bitmap.createBitmap(
        targetWidth,
        targetHeight,
        Bitmap.Config.ARGB_8888);
    Canvas canvas = new Canvas(targetBitmap);
    
	// Adapted from
	// http://stackoverflow.com/questions/1705239/how-should-i-give-images-rounded-corners-in-android
	Bitmap rounder = Bitmap.createBitmap(targetWidth, targetHeight,
			Bitmap.Config.ARGB_8888);
	Canvas canvasRounder = new Canvas(rounder);
	Paint xferPaint = new Paint(Paint.ANTI_ALIAS_FLAG);
	xferPaint.setColor(Color.RED);
	canvasRounder.drawRoundRect(new RectF(0, 0, targetWidth, targetHeight),
			mRadius, mRadius, xferPaint);
	xferPaint.setXfermode(new PorterDuffXfermode(PorterDuff.Mode.DST_IN));

	// Create a private image view to do scaling stuff. Saves us a lot of tricky calculations
	// to achieve "CenterCrop" scale type... =)
	ImageView ivCopy = new ImageView(this.getContext());
	ivCopy.setScaleType(ScaleType.CENTER_CROP);		
	ivCopy.setImageBitmap(mBitmap);
	ivCopy.measure(MeasureSpec.makeMeasureSpec(targetWidth, MeasureSpec.EXACTLY),
					MeasureSpec.makeMeasureSpec(targetHeight, MeasureSpec.EXACTLY));
	ivCopy.layout(0, 0, targetWidth, targetHeight);
	
	canvas.save();
	ivCopy.draw(canvas);
	canvas.restore();
	canvas.drawBitmap(rounder, 0, 0, xferPaint);

    super.setImageBitmap(targetBitmap);
}