/*
* Copyright (C) 2006 The Android Open Source Project
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package android.widget;
import android.content.Context;
import android.content.res.TypedArray;
import android.util.AttributeSet;
import android.view.View;
import android.view.ViewGroup;
import android.widget.RemoteViews.RemoteView;
/**
* 让你指定其子元素的精确位置（x/y坐标）的布局.绝对布局缺乏灵活性，
* 相比其他不指定绝对位置的布局更难于维护。
*
* <p><strong>XML 属性</strong></p> <p> 参见 {@link
* android.R.styleable#ViewGroup ViewGroup 属性} 和 {@link
* android.R.styleable#View View >属性}。</p>
*
* @deprecated 用 {@link android.widget.FrameLayout}、{@link android.widget.RelativeLayout}
* 或者自定义布局代替。
* @author translate by madgoat
* @author translate by 绵白糖
* @author review by cnmahj
* @author convert by cnmahj
*/
@Deprecated
@RemoteView
public class AbsoluteLayout extends ViewGroup {
public AbsoluteLayout(Context context) {
super(context);
}
public AbsoluteLayout(Context context, AttributeSet attrs) {
super(context, attrs);
}
public AbsoluteLayout(Context context, AttributeSet attrs,
int defStyle) {
super(context, attrs, defStyle);
}
@Override
protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {
int count = getChildCount();
int maxHeight = 0;
int maxWidth = 0;
// Find out how big everyone wants to be
measureChildren(widthMeasureSpec, heightMeasureSpec);
// Find rightmost and bottom-most child
for (int i = 0; i < count; i++) {
View child = getChildAt(i);
if (child.getVisibility() != GONE) {
int childRight;
int childBottom;
AbsoluteLayout.LayoutParams lp
= (AbsoluteLayout.LayoutParams) child.getLayoutParams();
childRight = lp.x + child.getMeasuredWidth();
childBottom = lp.y + child.getMeasuredHeight();
maxWidth = Math.max(maxWidth, childRight);
maxHeight = Math.max(maxHeight, childBottom);
}
}
// Account for padding too
maxWidth += mPaddingLeft + mPaddingRight;
maxHeight += mPaddingTop + mPaddingBottom;
// Check against minimum height and width
maxHeight = Math.max(maxHeight, getSuggestedMinimumHeight());
maxWidth = Math.max(maxWidth, getSuggestedMinimumWidth());
setMeasuredDimension(resolveSizeAndState(maxWidth, widthMeasureSpec, 0),
resolveSizeAndState(maxHeight, heightMeasureSpec, 0));
}
/**
* 返回一组宽度为 {@link android.view.ViewGroup.LayoutParams#WRAP_CONTENT}、
* 高度为 {@link android.view.ViewGroup.LayoutParams#WRAP_CONTENT}、
* 坐标是（0，0）的布局参数。
*/
@Override
protected ViewGroup.LayoutParams generateDefaultLayoutParams() {
return new LayoutParams(LayoutParams.WRAP_CONTENT, LayoutParams.WRAP_CONTENT, 0, 0);
}
@Override
protected void onLayout(boolean changed, int l, int t,
int r, int b) {
int count = getChildCount();
for (int i = 0; i < count; i++) {
View child = getChildAt(i);
if (child.getVisibility() != GONE) {
AbsoluteLayout.LayoutParams lp =
(AbsoluteLayout.LayoutParams) child.getLayoutParams();
int childLeft = mPaddingLeft + lp.x;
int childTop = mPaddingTop + lp.y;
child.layout(childLeft, childTop,
childLeft + child.getMeasuredWidth(),
childTop + child.getMeasuredHeight());
}
}
}
@Override
public ViewGroup.LayoutParams generateLayoutParams(AttributeSet attrs) {
return new AbsoluteLayout.LayoutParams(getContext(), attrs);
}
// Override to allow type-checking of LayoutParams.
@Override
protected boolean checkLayoutParams(ViewGroup.LayoutParams p) {
return p instanceof AbsoluteLayout.LayoutParams;
}
@Override
protected ViewGroup.LayoutParams generateLayoutParams(ViewGroup.LayoutParams p) {
return new LayoutParams(p);
}
@Override
public boolean shouldDelayChildPressedState() {
return false;
}
/**
* 与 AbsoluteLayout 关联的子元素的布局信息.参见绝对布局属性中该类所支持的子视图属性列表。
* 该类支持的所有子视图属性列表，参见
* {@link android.R.styleable#AbsoluteLayout_Layout 绝对布局属性}。
*/
public static class LayoutParams extends ViewGroup.LayoutParams {
/**
* 视图组中子视图的横（X）坐标。
*/
public int x;
/**
* 视图组中子视图的纵（Y）坐标。
*/
public int y;
/**
* 根据指定的宽度、高度和位置创建新的布局参数集合。
*
* @param width {@link #MATCH_PARENT}、{@link #WRAP_CONTENT}
* 或者已像素为单位的宽度
* @param height {@link #MATCH_PARENT}、{@link #WRAP_CONTENT}
* 或者已像素为单位的高度
* @param x 子视图的横（X）坐标
* @param y 子视图的纵（Y）坐标
*/
public LayoutParams(int width, int height, int x, int y) {
super(width, height);
this.x = x;
this.y = y;
}
/**
* 创建新的布局参数集合.其值来自于提供的上下文和属性集合。
* XML 属性映射关系如下：
*
* <ul>
* <li><code>layout_x</code>：子视图的横（X）坐标。</li>
* <li><code>layout_y</code>：子视图的纵（Y）坐标。</li>
* <li>所有来自 {@link android.view.ViewGroup.LayoutParams} 的 XML 属性。</li>
* </ul>
*
* @param c 应用程序上下文
* @param attrs 用于提取布局属性值的属性集合
*/
public LayoutParams(Context c, AttributeSet attrs) {
super(c, attrs);
TypedArray a = c.obtainStyledAttributes(attrs,
com.android.internal.R.styleable.AbsoluteLayout_Layout);
x = a.getDimensionPixelOffset(
com.android.internal.R.styleable.AbsoluteLayout_Layout_layout_x, 0);
y = a.getDimensionPixelOffset(
com.android.internal.R.styleable.AbsoluteLayout_Layout_layout_y, 0);
a.recycle();
}
/**
* {@inheritDoc}
*/
public LayoutParams(ViewGroup.LayoutParams source) {
super(source);
}
@Override
public String debug(String output) {
return output + "Absolute.LayoutParams={width="
+ sizeToString(width) + ", height=" + sizeToString(height)
+ " x=" + x + " y=" + y + "}";
}
}
}