具有讽刺意味的是,当我回答另一个question
时,我偶然发现了一个问题问题在于,如果我将RelativeLayout添加为ICGridLayout的子级,那么RelativeLayout的子级就不会获得RelativeLayout.LayoutParams。这适用于我添加到ICGridLayout的各种布局。我已经阅读了LinearLayout,RelativeLayout,AbsoluteLayout和ViewGroup的源代码,但是没有发现任何能让我暗示我做错的地方。我还看了Romain Guy的指南创建了一个FlowLayout,希望得到一个答案,唉,这没有发生。
修改
添加了我的layout.xml文件。似乎孩子们回应上面,下面,左边,右边和右边缘,但不是其他相对布局规则。
如您所见,我使用简单的XML布局。
即使他们的孩子回应了上述规则,eclipse(和android studio)自动完成也无法识别xml属性。
结束编辑
我的attrs.xml文件:
<?xml version="1.0" encoding="utf-8"?>
<resources>
<declare-styleable name="ICGridLayout_Layout">
<attr name="columns" format="integer"/>
<attr name="layout_left" format="integer"/>
<attr name="layout_top" format="integer"/>
<attr name="layout_right" format="integer"/>
<attr name="layout_bottom" format="integer"/>
<attr name="layout_col_span" format="integer"/>
<attr name="layout_row_span" format="integer"/>
<attr name="layout_spacing" format="dimension"/>
</declare-styleable>
</resources>
我的ICGridLayout.java文件:
package com.risch.evertsson.iclib.layout;
import android.content.Context;
import android.content.res.TypedArray;
import android.util.AttributeSet;
import android.view.View;
import android.view.ViewGroup;
import android.widget.LinearLayout;
import android.widget.RemoteViews.RemoteView;
import com.risch.evertsson.iclib.R;
/**
* Created by johanrisch on 6/13/13.
*/
@RemoteView
public class ICGridLayout extends ViewGroup {
private int mColumns = 4;
private float mSpacing;
public ICGridLayout(Context context) {
super(context);
}
public ICGridLayout(Context context, AttributeSet attrs) {
super(context, attrs);
init(attrs);
}
public ICGridLayout(Context context, AttributeSet attrs, int defStyle) {
super(context, attrs, defStyle);
init(attrs);
}
private void init(AttributeSet attrs) {
TypedArray a = getContext().obtainStyledAttributes(
attrs,
R.styleable.ICGridLayout_Layout);
this.mColumns = a.getInt(R.styleable.ICGridLayout_Layout_columns, 3);
this.mSpacing = a.getDimension(R.styleable.ICGridLayout_Layout_layout_spacing, 0);
a.recycle();
}
@Override
protected void onLayout(boolean changed, int l, int t, int r, int b) {
if (changed) {
int width = (int) (r - l);
int side = width / mColumns;
int children = getChildCount();
View child = null;
for (int i = 0; i < children; i++) {
child = getChildAt(i);
LayoutParams lp = (LayoutParams) child.getLayoutParams();
int left = (int) (lp.left * side + mSpacing / 2);
int right = (int) (lp.right * side - mSpacing / 2);
int top = (int) (lp.top * side + mSpacing / 2);
int bottom = (int) (lp.bottom * side - mSpacing / 2);
child.layout(left, top, right, bottom);
}
}
}
@Override
protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {
measureVertical(widthMeasureSpec, heightMeasureSpec);
}
private void measureVertical(int widthMeasureSpec, int heightMeasureSpec) {
int widthMode = MeasureSpec.getMode(widthMeasureSpec);
int heightMode = MeasureSpec.getMode(heightMeasureSpec);
int width = 0;
int height = 0;
if (widthMode == MeasureSpec.AT_MOST || widthMode == MeasureSpec.EXACTLY) {
width = MeasureSpec.getSize(widthMeasureSpec);
} else {
throw new RuntimeException("widthMeasureSpec must be AT_MOST or " +
"EXACTLY not UNSPECIFIED when orientation == VERTICAL");
}
View child = null;
int row = 0;
int side = width / mColumns;
int childCount = getChildCount();
for (int i = 0; i < childCount; i++) {
child = getChildAt(i);
LayoutParams lp = (LayoutParams) child.getLayoutParams();
if (lp.bottom > row) {
row = lp.bottom;
}
int childHeight = (lp.bottom - lp.top)*side;
int childWidth = (lp.right-lp.left)*side;
int heightSpec = getChildMeasureSpec(heightMeasureSpec, 0, childHeight);
int widthSpec = getChildMeasureSpec(widthMeasureSpec, 0, childWidth);
// measureChild(child, widthMeasureSpec, heightMeasureSpec);
child.measure(widthSpec, heightSpec);
}
height = row * side;
// TODO: Figure out a good way to use the heightMeasureSpec...
setMeasuredDimension(width, height);
}
@Override
public ViewGroup.LayoutParams generateLayoutParams(AttributeSet attrs) {
return new ICGridLayout.LayoutParams(getContext(), attrs);
}
@Override
protected boolean checkLayoutParams(ViewGroup.LayoutParams p) {
return p instanceof ICGridLayout.LayoutParams;
}
@Override
protected ViewGroup.LayoutParams
generateLayoutParams(ViewGroup.LayoutParams p) {
return new ICGridLayout.LayoutParams(p);
}
protected ViewGroup.LayoutParams
generateLayoutParams(ViewGroup.MarginLayoutParams p) {
return new ICGridLayout.LayoutParams(p);
}
@Override
protected ViewGroup.LayoutParams generateDefaultLayoutParams() {
return new LayoutParams();
}
public static class LayoutParams extends ViewGroup.MarginLayoutParams {
int right = 1;
int bottom = 1;
int top = 0;
int left = 0;
int width = -1;
int height = -1;
public LayoutParams() {
super(MATCH_PARENT, MATCH_PARENT);
top = 0;
left = 1;
}
public LayoutParams(int width, int height) {
super(width, height);
top = 0;
left = 1;
}
public LayoutParams(Context context, AttributeSet attrs) {
super(context, attrs);
TypedArray a = context.obtainStyledAttributes(
attrs,
R.styleable.ICGridLayout_Layout);
left = a.getInt(R.styleable.ICGridLayout_Layout_layout_left, 0);
top = a.getInt(R.styleable.ICGridLayout_Layout_layout_top, 0);
right = a.getInt(R.styleable.ICGridLayout_Layout_layout_right, left + 1);
bottom = a.getInt(R.styleable.ICGridLayout_Layout_layout_bottom, top + 1);
height = a.getInt(R.styleable.ICGridLayout_Layout_layout_row_span, -1);
width = a.getInt(R.styleable.ICGridLayout_Layout_layout_col_span, -1);
if (height != -1) {
bottom = top + height;
}
if (width != -1) {
right = left + width;
}
a.recycle();
}
public LayoutParams(ViewGroup.LayoutParams params) {
super(params);
}
public LayoutParams(ViewGroup.MarginLayoutParams params) {
super(params);
}
}
}
我的layout.xml文件:
<com.risch.evertsson.iclib.layout.ICGridLayout
android:id="@+id/ICGridLayout1"
android:layout_width="match_parent"
android:layout_height="match_parent"
app:spacing="4dp"
app:columns="4" >
<RelativeLayout
android:layout_width="match_parent"
android:layout_height="match_parent"
app:layout_bottom="8"
app:layout_left="0"
app:layout_right="4"
app:layout_top="0" >
<Button
android:id="@+id/button"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_alignParentLeft="true"
android:layout_alignParentTop="true"
android:layout_marginLeft="90dp"
android:layout_marginTop="109dp"
android:text="Button" />
<LinearLayout
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_marginBottom="16dp"
android:background="#ffffff"
android:layout_marginLeft="0dp"
android:centerHorizontal="true"
android:layout_below="@+id/button"
android:orientation="vertical" >
<Button
android:id="@+id/button1"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_alignParentLeft="true"
android:layout_alignParentTop="true"
android:layout_marginLeft="90dp"
android:layout_marginTop="109dp"
android:text="Button" />
</LinearLayout>
</RelativeLayout>
</com.risch.evertsson.iclib.layout.ICGridLayout>
我花了至少5个小时浏览SO和谷歌以找到答案,这就是我写自己的问题的原因。
提前致谢。 --Johan Risch