Java Code Examples for android.view.View#layout()

@Override
protected void onLayout(boolean changed, int left, int top, int right,
		int bottom) {

	final int count = getChildCount();

	int cLeft = 0;

	for (int i = 0; i < count; i++) {
		View child = getChildAt(i);
		if (child.getVisibility() == View.GONE)
			continue;

		// child.setVisibility(View.VISIBLE);
		final int childWidth = child.getMeasuredWidth();
		child.layout(cLeft, 0, cLeft + childWidth,
				child.getMeasuredHeight());

		cLeft += childWidth;
	}

}
 

public Bitmap createWidgetBitmap(ItemInfo widgetInfo, View layout) {
    int[] unScaledSize = mLauncher.getWorkspace().estimateItemSize(widgetInfo.spanX,
            widgetInfo.spanY, widgetInfo, false);
    int visibility = layout.getVisibility();
    layout.setVisibility(VISIBLE);

    int width = MeasureSpec.makeMeasureSpec(unScaledSize[0], MeasureSpec.EXACTLY);
    int height = MeasureSpec.makeMeasureSpec(unScaledSize[1], MeasureSpec.EXACTLY);
    Bitmap b = Bitmap.createBitmap(unScaledSize[0], unScaledSize[1],
            Bitmap.Config.ARGB_8888);
    Canvas c = new Canvas(b);

    layout.measure(width, height);
    layout.layout(0, 0, unScaledSize[0], unScaledSize[1]);
    layout.draw(c);
    c.setBitmap(null);
    layout.setVisibility(visibility);
    return b;
}
 

@Override
protected void onLayout(boolean changed, int l, int t, int r, int b) {

	childCount = getChildCount(); // 获取子视图数
	childWidth = childCount > 0 ? getChildAt(0).getMeasuredWidth() : 0; // 获取字节点的宽度
	if (!setShareWindowFlag && defaultWindow >= 0
			&& defaultWindow <= childCount - 1) {
		// 设置默认窗口的左端距离
		offset = -1 * defaultWindow * childWidth;
		setShareWindowFlag = true;
	}
	// 设置距离(0,0)点X轴方向的初始距离
	int left = 0 + offset;
	for (int i = 0; i < childCount; i++) {
		// 设置每个子视图在布局中的位置
		View child = getChildAt(i);
		if (child.getVisibility() != View.GONE) {
			child.layout(left, 0, childWidth + left,
					child.getMeasuredHeight());
			left = left + childWidth;
		}
	}
}
 

@TargetApi(Build.VERSION_CODES.HONEYCOMB)
public static Bitmap b(View view) {
    Bitmap bitmap = null;
    view.measure(View.MeasureSpec.makeMeasureSpec(0, 0),
            View.MeasureSpec.makeMeasureSpec(0, 0));
    int i = view.getMeasuredWidth();
    int j = view.getMeasuredHeight();
    view.layout(0, 0, i, j);
    view.setDrawingCacheEnabled(false);
    view.setWillNotCacheDrawing(true);
    view.setDrawingCacheEnabled(false);
    view.setWillNotCacheDrawing(true);
    if (i > 0 && j > 0) {
        bitmap = Bitmap.createBitmap(i, j,
                Bitmap.Config.ARGB_8888);
        Canvas canvas = new Canvas(bitmap);
        if (Build.VERSION.SDK_INT >= 11)
            view.setLayerType(1, null);
        view.draw(canvas);
    }
    return bitmap;
}
 

protected int positionChild(View child, int x, int y, int contentHeight) {
    int childWidth = child.getMeasuredWidth();
    int childHeight = child.getMeasuredHeight();
    int childTop = y + (contentHeight - childHeight) / 2;

    child.layout(x, childTop, x + childWidth, childTop + childHeight);

    return childWidth;
}
 

protected int positionChildInverse(View child, int x, int y, int contentHeight) {
    int childWidth = child.getMeasuredWidth();
    int childHeight = child.getMeasuredHeight();
    int childTop = y + (contentHeight - childHeight) / 2;

    child.layout(x - childWidth, childTop, x, childTop + childHeight);

    return childWidth;
}
 

@Override
public void computeScroll() {
    if (scroller.computeScrollOffset()) {
        View view = getChildAt(1);
        int left = startScrollLeftOffset + scroller.getCurrX();
        view.layout(left, view.getTop(), left + view.getWidth(),
                view.getHeight());
        postInvalidate();
    }
}
 

@Override
protected void onLayout(boolean changed, int l, int t, int r, int b) {
    final int count = getChildCount();
    for (int i = 0; i < count; i++) {
        View child = getChildAt(i);
        LayoutParams lp = (LayoutParams) child.getLayoutParams();
        child.layout(lp.x, lp.y, lp.x + child.getMeasuredWidth(), lp.y + child.getMeasuredHeight());
    }
}
 

@Override
protected void onLayout(boolean changed, int left, int top, int right, int bottom) {
    final View child = getChildAt(0);

    if (child == null) {
        return;
    }

    if (mGravity == Gravity.TOP) {
        child.layout(0, 0, getMeasuredWidth(), child.getMeasuredHeight());
    } else {
        child.layout(0, getMeasuredHeight() - child.getMeasuredHeight(), getMeasuredWidth(), getMeasuredHeight());
    }
}
 

@Override
protected void onLayout(boolean changed, int l, int t, int r, int b) {
    int childCount = getChildCount();// 获取子组件数
    int row = 1;// 子组件行数,初始化赋值为1
    int left = 0;// 子组件的左边“坐标”
    int right = 0;// 子组件的右边“坐标”
    int top = 0;// 子组件的顶部“坐标”
    int bottom = 0;// 子组件的底部“坐标”
    int p = getPaddingLeft();// 在父组件中设置的padding属性的值,该值显然也会影响到子组件在屏幕的显示位置
    for (int i = 0; i < childCount; i++) {
        View view = getChildAt(i);
        int width = view.getMeasuredWidth();// 测量子组件的宽
        int height = view.getMeasuredHeight();// 测量子组件的高
        left = p + right;// ---------------------------------------------------备注1
        right = left + width;// -----------------------------------------------备注2
        top = p * row + height * (row - 1);// ---------------------------------备注3
        bottom = top + height;// ----------------------------------------------备注4
        if (right > maxWidth) {
            row++;
            left = 0;//每次换行后要将子组件左边“坐标”与右边“坐标”重新初始化
            right = 0;
            left = p + right ;
            right = left + width;
            top = p * row + height * (row - 1);
            bottom = top + height;
        }
        view.layout(left, top, right, bottom);// 最后按照计算出来的“坐标”将子组件放在父容器内
    }
}
 

public Bitmap loadBitmapFromView(View view) {
  if (view.getMeasuredHeight() <= 0) {
    view.measure(LayoutParams.WRAP_CONTENT, LayoutParams.WRAP_CONTENT);
  }
  Bitmap bitmap = Bitmap.createBitmap(view.getMeasuredWidth(), view.getMeasuredHeight(),
      Bitmap.Config.ARGB_8888);
  Canvas canvas = new Canvas(bitmap);
  view.layout(0, 0, view.getMeasuredWidth(), view.getMeasuredHeight());
  loadedBitmap = true;
  view.draw(canvas);
  return bitmap;
}
 

@Override
protected void onLayout(boolean changed,
                        int l, int t, int r, int b) {
    int childCount = getChildCount();
    // 设置ViewGroup的高度
    MarginLayoutParams mlp = (MarginLayoutParams) getLayoutParams();
    mlp.height = mScreenHeight * childCount;
    setLayoutParams(mlp);
    for (int i = 0; i < childCount; i++) {
        View child = getChildAt(i);
        if (child.getVisibility() != View.GONE) {
            child.layout(l, i * mScreenHeight,r, (i + 1) * mScreenHeight);
        }
    }
}
 

/**
 * 当菜单被ContentView遮住的时候，要设置菜单为Invisible，防止已隐藏的菜单接收到点击事件。
 */
private void updateMenu() {
    View contentView = getContentView();
    if (contentView != null) {
        int contentLeft = contentView.getLeft();
        if (contentLeft == 0) {
            for (View view : mMenus.values()) {
                if (checkAbsoluteGravity(view, Gravity.LEFT)) {
                    view.layout(-view.getWidth(), view.getTop(), 0, view.getBottom());
                } else {
                    view.layout(getMeasuredWidth(), view.getTop(),
                            getMeasuredWidth() + view.getMeasuredWidth(), view.getBottom());
                }
            }
        } else {
            if (mCurrentMenu != null && mCurrentMenu.getLeft() != 0) {
                if (isLeftMenu()) {
                    mCurrentMenu.layout(0, mCurrentMenu.getTop(),
                            mCurrentMenu.getMeasuredWidth(), mCurrentMenu.getBottom());
                } else {
                    mCurrentMenu.layout(
                            getMeasuredWidth() - mCurrentMenu.getMeasuredWidth(),
                            mCurrentMenu.getTop(),
                            getMeasuredWidth(),
                            mCurrentMenu.getBottom());
                }
            }
        }
    }
}
 

@Override
protected void onLayout(final boolean changed, final int l, final int t,
                        final int r, final int b) {
    int maxWidth = r - l;
    int line = 1;
    int xPos = 0;
    int padding = 12;
    int size = getChildCount();
    for (int i = 0; i < size; ++i) {
        final View child = getChildAt(i);
        int w = child.getMeasuredWidth();
        int h = child.getMeasuredHeight();

        if (xPos + w + padding > maxWidth) {
            // break line
            line++;
            xPos = 0;
        }
        int left = xPos + padding;
        int top = maxLineHeight * line;
        int right = left + w;
        int bottom = top + h;
        child.layout(left, top, right, bottom);
        xPos += w + padding;
    }

}
 

@Override
protected void onLayout(boolean changed, int l, int t, int r, int b) {
    if (mTracking) {
        return;
    }

    final int width = r - l;
    final int height = b - t;

    final View handle = mHandle;

    int childWidth = handle.getMeasuredWidth();
    int childHeight = handle.getMeasuredHeight();

    int childLeft;
    int childTop;

    final View content = mContent;

    if (mVertical) {
        childLeft = (width - childWidth) / 2;
        childTop = mExpanded ? mTopOffset : height - childHeight + mBottomOffset;

        content.layout(0, mTopOffset + childHeight, content.getMeasuredWidth(),
                mTopOffset + childHeight + content.getMeasuredHeight());
    } else {
        childLeft = mExpanded ? mTopOffset : width - childWidth + mBottomOffset;
        childTop = (height - childHeight) / 2;

        content.layout(mTopOffset + childWidth, 0,
                mTopOffset + childWidth + content.getMeasuredWidth(),
                content.getMeasuredHeight());            
    }

    handle.layout(childLeft, childTop, childLeft + childWidth, childTop + childHeight);
    mHandleHeight = handle.getHeight();
    mHandleWidth = handle.getWidth();
}
 

private Bitmap loadBitmap(int width, int height, int index) {
    LayoutInflater inflater = (LayoutInflater)getSystemService(Context.LAYOUT_INFLATER_SERVICE);
    View v = inflater.inflate(mBitmapIds[index],null);
    v.measure(MeasureSpec.makeMeasureSpec(width,MeasureSpec.EXACTLY), MeasureSpec.makeMeasureSpec(height, MeasureSpec.EXACTLY));
    v.layout(0, 0, v.getMeasuredWidth(), v.getMeasuredHeight());
    Bitmap b = Bitmap.createBitmap(v.getWidth(), v.getHeight(),Bitmap.Config.ARGB_8888);
    Canvas c = new Canvas(b);
    v.draw(c);
    return b;
}
 

/**
 * Return the bitmap of screen.
 *
 * @param activity          The activity.
 * @param isDeleteStatusBar True to delete status bar, false otherwise.
 * @return the bitmap of screen
 */
public static Bitmap screenShot(@NonNull final Activity activity, boolean isDeleteStatusBar) {
    View decorView = activity.getWindow().getDecorView();
    boolean drawingCacheEnabled = decorView.isDrawingCacheEnabled();
    boolean willNotCacheDrawing = decorView.willNotCacheDrawing();
    decorView.setDrawingCacheEnabled(true);
    decorView.setWillNotCacheDrawing(false);
    Bitmap bmp = decorView.getDrawingCache();
    if (bmp == null) {
        decorView.measure(View.MeasureSpec.makeMeasureSpec(0, View.MeasureSpec.UNSPECIFIED),
                View.MeasureSpec.makeMeasureSpec(0, View.MeasureSpec.UNSPECIFIED));
        decorView.layout(0, 0, decorView.getMeasuredWidth(), decorView.getMeasuredHeight());
        decorView.buildDrawingCache();
        bmp = Bitmap.createBitmap(decorView.getDrawingCache());
    }
    if (bmp == null) {
        return null;
    }
    DisplayMetrics dm = new DisplayMetrics();
    activity.getWindowManager().getDefaultDisplay().getMetrics(dm);
    Bitmap ret;
    if (isDeleteStatusBar) {
        Resources resources = activity.getResources();
        int resourceId = resources.getIdentifier("status_bar_height", "dimen", "android");
        int statusBarHeight = resources.getDimensionPixelSize(resourceId);
        ret = Bitmap.createBitmap(bmp,
                0,
                statusBarHeight,
                dm.widthPixels,
                dm.heightPixels - statusBarHeight);
    } else {
        ret = Bitmap.createBitmap(bmp, 0, 0, dm.widthPixels, dm.heightPixels);
    }
    decorView.destroyDrawingCache();
    decorView.setWillNotCacheDrawing(willNotCacheDrawing);
    decorView.setDrawingCacheEnabled(drawingCacheEnabled);
    return ret;
}
 

protected void onLayout(boolean flag, int i, int j, int k, int i1)
{
    int j1;
    int k1;
    int l1;
    j1 = getPaddingLeft();
    k1 = getPaddingTop();
    l1 = getSlidingTop();
    int i2 = getChildCount();
    if (mFirstLayout)
    {
        int j2;
        switch (l.a[mSlideState.ordinal()])
        {
        default:
            mSlideOffset = 1.0F;
            break;

        case 1: // '\001'
            float f1;
            if (mCanSlide)
            {
                f1 = 0.0F;
            } else
            {
                f1 = 1.0F;
            }
            mSlideOffset = f1;
            continue;

        case 2: // '\002'
            float f;
            if (mCanSlide)
            {
                f = mAnchorPoint;
            } else
            {
                f = 1.0F;
            }
            mSlideOffset = f;
            continue;
        }
        break;
    }
    do
    {
        j2 = 0;
        while (j2 < i2) 
        {
            View view = getChildAt(j2);
            if (view.getVisibility() != 8)
            {
                LayoutParams layoutparams = (LayoutParams)view.getLayoutParams();
                int k2 = view.getMeasuredHeight();
                if (layoutparams.slideable)
                {
                    mSlideRange = k2 - mPanelHeight;
                }
                int l2;
                if (mIsSlidingUp)
                {
                    int i3;
                    int j3;
                    if (layoutparams.slideable)
                    {
                        j3 = l1 + (int)((float)mSlideRange * mSlideOffset);
                    } else
                    {
                        j3 = k1;
                    }
                    l2 = j3;
                } else
                {
                    if (layoutparams.slideable)
                    {
                        l2 = l1 - (int)((float)mSlideRange * mSlideOffset);
                    } else
                    {
                        l2 = k1;
                    }
                    if (!layoutparams.slideable && !mOverlayContent)
                    {
                        l2 += mPanelHeight;
                    }
                }
                i3 = l2 + k2;
                view.layout(j1, l2, j1 + view.getMeasuredWidth(), i3);
            }
            j2++;
        }
        if (mFirstLayout)
        {
            updateObscuredViewVisibility();
        }
        mFirstLayout = false;
        return;
    } while (true);
}
 

/**
 * 可以绘制在内容的上面，覆盖内容
 *
 * @param c
 * @param parent
 * @param state
 */
@RequiresApi(api = Build.VERSION_CODES.KITKAT)
@Override
public void onDrawOver(Canvas c, final RecyclerView parent, RecyclerView.State state) {
    // 当前屏幕的第一个item
    int pos = ((LinearLayoutManager) (parent.getLayoutManager())).findFirstVisibleItemPosition();
    String tag = mDatas.get(pos).getTag();
    Log.e(TAG, "onDrawOver: pos：" + pos + "\ttag：" + tag);
    View child = parent.findViewHolderForLayoutPosition(pos).itemView;
    // 当发现下一个title顶上来的时候，将canvas向上平移，产生一种向上挤压的动画效果
    boolean flag = false;
    if ((pos + 1) < mDatas.size()) {
        String suspensionTag = mDatas.get(pos + 1).getTag();
        if (null != tag && !tag.equals(suspensionTag)) {
            if (child.getHeight() + child.getTop() < mTitleHeight) {
                c.save();
                flag = true;
                c.translate(0, child.getHeight() + child.getTop() - mTitleHeight);
            }
        }
    }

    // 绘制一个与列表中标题一样的东西（吸顶效果）
    View topTitleView = mInflater.inflate(R.layout.item_title, parent, false);
    TextView tvTitle = (TextView) topTitleView.findViewById(R.id.tv_title);
    tvTitle.setText("测试数据" + tag);
    int toDrawWidthSpec;//用于测量的widthMeasureSpec
    int toDrawHeightSpec;//用于测量的heightMeasureSpec
    RecyclerView.LayoutParams lp = (RecyclerView.LayoutParams) topTitleView.getLayoutParams();
    if (lp == null) {
        lp = new RecyclerView.LayoutParams(ViewGroup.LayoutParams.MATCH_PARENT, ViewGroup.LayoutParams.WRAP_CONTENT);//这里是根据复杂布局layout的width height，new一个Lp
        // topTitleView.setLayoutParams(lp);
    }
    topTitleView.setLayoutParams(lp);
    if (lp.width == ViewGroup.LayoutParams.MATCH_PARENT) {
        //如果是MATCH_PARENT，则用父控件能分配的最大宽度和EXACTLY构建MeasureSpec。
        toDrawWidthSpec = View.MeasureSpec.makeMeasureSpec(parent.getWidth() - parent.getPaddingLeft() - parent.getPaddingRight(), View.MeasureSpec.EXACTLY);
    } else if (lp.width == ViewGroup.LayoutParams.WRAP_CONTENT) {
        //如果是WRAP_CONTENT，则用父控件能分配的最大宽度和AT_MOST构建MeasureSpec。
        toDrawWidthSpec = View.MeasureSpec.makeMeasureSpec(parent.getWidth() - parent.getPaddingLeft() - parent.getPaddingRight(), View.MeasureSpec.AT_MOST);
    } else {
        //否则则是具体的宽度数值，则用这个宽度和EXACTLY构建MeasureSpec。
        toDrawWidthSpec = View.MeasureSpec.makeMeasureSpec(lp.width, View.MeasureSpec.EXACTLY);
    }
    //高度同理
    if (lp.height == ViewGroup.LayoutParams.MATCH_PARENT) {
        toDrawHeightSpec = View.MeasureSpec.makeMeasureSpec(parent.getHeight() - parent.getPaddingTop() - parent.getPaddingBottom(), View.MeasureSpec.EXACTLY);
    } else if (lp.height == ViewGroup.LayoutParams.WRAP_CONTENT) {
        toDrawHeightSpec = View.MeasureSpec.makeMeasureSpec(parent.getHeight() - parent.getPaddingTop() - parent.getPaddingBottom(), View.MeasureSpec.AT_MOST);
    } else {
        toDrawHeightSpec = View.MeasureSpec.makeMeasureSpec(mTitleHeight, View.MeasureSpec.EXACTLY);
    }
    //依次调用 measure,layout,draw方法，将复杂头部显示在屏幕上。
    topTitleView.measure(toDrawWidthSpec, toDrawHeightSpec);
    topTitleView.layout(parent.getPaddingLeft(), parent.getPaddingTop(), parent.getPaddingLeft() + topTitleView.getMeasuredWidth(), parent.getPaddingTop() + topTitleView.getMeasuredHeight());
    topTitleView.draw(c);//Canvas默认在视图顶部，无需平移，直接绘制
    if (flag)
        c.restore();//恢复画布到之前保存的状态
    if (!TextUtils.equals(tag, currentTag)) {
        currentTag = tag;
        Integer integer = Integer.valueOf(currentTag);
        Log.e(TAG, "onDrawOver: " + integer);
        mCheckListener.check(integer);
    }

}
 

protected void onLayoutChild(View child, int position, int l, int t, int r, int b) {
	child.layout(l, t, r, b);
}