私はこれと非常によく似たものを実装しましたが、間隔とパディングを処理するためのもう少し標準的な方法だと思います。皆さんの考えを私に知らせてください、そして帰属なしで自由に再利用してください：
package com.asolutions.widget;
import java.util.ArrayList;
import java.util.Collections;
import java.util.Iterator;
import java.util.List;
import android.content.Context;
import android.content.res.TypedArray;
import android.util.AttributeSet;
import android.view.View;
import android.view.ViewGroup;
import com.asolutions.widget.R;
public class RowLayout extends ViewGroup {
public static final int DEFAULT_HORIZONTAL_SPACING = 5;
public static final int DEFAULT_VERTICAL_SPACING = 5;
private final int horizontalSpacing;
private final int verticalSpacing;
private List<RowMeasurement> currentRows = Collections.emptyList();
public RowLayout(Context context, AttributeSet attrs) {
super(context, attrs);
TypedArray styledAttributes = context.obtainStyledAttributes(attrs, R.styleable.RowLayout);
horizontalSpacing = styledAttributes.getDimensionPixelSize(R.styleable.RowLayout_android_horizontalSpacing,
DEFAULT_HORIZONTAL_SPACING);
verticalSpacing = styledAttributes.getDimensionPixelSize(R.styleable.RowLayout_android_verticalSpacing,
DEFAULT_VERTICAL_SPACING);
styledAttributes.recycle();
}
@Override
protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {
final int widthMode = MeasureSpec.getMode(widthMeasureSpec);
final int heightMode = MeasureSpec.getMode(heightMeasureSpec);
final int maxInternalWidth = MeasureSpec.getSize(widthMeasureSpec) - getHorizontalPadding();
final int maxInternalHeight = MeasureSpec.getSize(heightMeasureSpec) - getVerticalPadding();
List<RowMeasurement> rows = new ArrayList<RowMeasurement>();
RowMeasurement currentRow = new RowMeasurement(maxInternalWidth, widthMode);
rows.add(currentRow);
for (View child : getLayoutChildren()) {
LayoutParams childLayoutParams = child.getLayoutParams();
int childWidthSpec = createChildMeasureSpec(childLayoutParams.width, maxInternalWidth, widthMode);
int childHeightSpec = createChildMeasureSpec(childLayoutParams.height, maxInternalHeight, heightMode);
child.measure(childWidthSpec, childHeightSpec);
int childWidth = child.getMeasuredWidth();
int childHeight = child.getMeasuredHeight();
if (currentRow.wouldExceedMax(childWidth)) {
currentRow = new RowMeasurement(maxInternalWidth, widthMode);
rows.add(currentRow);
}
currentRow.addChildDimensions(childWidth, childHeight);
}
int longestRowWidth = 0;
int totalRowHeight = 0;
for (int index = 0; index < rows.size(); index++) {
RowMeasurement row = rows.get(index);
totalRowHeight += row.getHeight();
if (index < rows.size() - 1) {
totalRowHeight += verticalSpacing;
}
longestRowWidth = Math.max(longestRowWidth, row.getWidth());
}
setMeasuredDimension(widthMode == MeasureSpec.EXACTLY ? MeasureSpec.getSize(widthMeasureSpec) : longestRowWidth
+ getHorizontalPadding(), heightMode == MeasureSpec.EXACTLY ? MeasureSpec.getSize(heightMeasureSpec)
: totalRowHeight + getVerticalPadding());
currentRows = Collections.unmodifiableList(rows);
}
private int createChildMeasureSpec(int childLayoutParam, int max, int parentMode) {
int spec;
if (childLayoutParam == LayoutParams.FILL_PARENT) {
spec = MeasureSpec.makeMeasureSpec(max, MeasureSpec.EXACTLY);
} else if (childLayoutParam == LayoutParams.WRAP_CONTENT) {
spec = MeasureSpec.makeMeasureSpec(max, parentMode == MeasureSpec.UNSPECIFIED ? MeasureSpec.UNSPECIFIED
: MeasureSpec.AT_MOST);
} else {
spec = MeasureSpec.makeMeasureSpec(childLayoutParam, MeasureSpec.EXACTLY);
}
return spec;
}
@Override
protected void onLayout(boolean changed, int leftPosition, int topPosition, int rightPosition, int bottomPosition) {
final int widthOffset = getMeasuredWidth() - getPaddingRight();
int x = getPaddingLeft();
int y = getPaddingTop();
Iterator<RowMeasurement> rowIterator = currentRows.iterator();
RowMeasurement currentRow = rowIterator.next();
for (View child : getLayoutChildren()) {
final int childWidth = child.getMeasuredWidth();
final int childHeight = child.getMeasuredHeight();
if (x + childWidth > widthOffset) {
x = getPaddingLeft();
y += currentRow.height + verticalSpacing;
if (rowIterator.hasNext()) {
currentRow = rowIterator.next();
}
}
child.layout(x, y, x + childWidth, y + childHeight);
x += childWidth + horizontalSpacing;
}
}
private List<View> getLayoutChildren() {
List<View> children = new ArrayList<View>();
for (int index = 0; index < getChildCount(); index++) {
View child = getChildAt(index);
if (child.getVisibility() != View.GONE) {
children.add(child);
}
}
return children;
}
protected int getVerticalPadding() {
return getPaddingTop() + getPaddingBottom();
}
protected int getHorizontalPadding() {
return getPaddingLeft() + getPaddingRight();
}
private final class RowMeasurement {
private final int maxWidth;
private final int widthMode;
private int width;
private int height;
public RowMeasurement(int maxWidth, int widthMode) {
this.maxWidth = maxWidth;
this.widthMode = widthMode;
}
public int getHeight() {
return height;
}
public int getWidth() {
return width;
}
public boolean wouldExceedMax(int childWidth) {
return widthMode == MeasureSpec.UNSPECIFIED ? false : getNewWidth(childWidth) > maxWidth;
}
public void addChildDimensions(int childWidth, int childHeight) {
width = getNewWidth(childWidth);
height = Math.max(height, childHeight);
}
private int getNewWidth(int childWidth) {
return width == 0 ? childWidth : width + horizontalSpacing + childWidth;
}
}
}
これには、/ res / values / attrs.xmlの下のエントリも必要です。まだ存在しない場合は作成できます。
<?xml version="1.0" encoding="utf-8"?>
<resources>
<declare-styleable name="RowLayout">
<attr name="android:verticalSpacing" />
<attr name="android:horizontalSpacing" />
</declare-styleable>
</resources>
xmlレイアウトでの使用法は次のようになります。
<?xml version="1.0" encoding="utf-8"?>
<com.asolutions.widget.RowLayout
xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_gravity="center"
android:padding="10dp"
android:horizontalSpacing="10dp"
android:verticalSpacing="20dp">
<FrameLayout android:layout_width="30px" android:layout_height="40px" android:background="#F00"/>
<FrameLayout android:layout_width="60px" android:layout_height="40px" android:background="#F00"/>
<FrameLayout android:layout_width="70px" android:layout_height="20px" android:background="#F00"/>
<FrameLayout android:layout_width="20px" android:layout_height="60px" android:background="#F00"/>
<FrameLayout android:layout_width="10px" android:layout_height="40px" android:background="#F00"/>
<FrameLayout android:layout_width="40px" android:layout_height="40px" android:background="#F00"/>
<FrameLayout android:layout_width="40px" android:layout_height="40px" android:background="#F00"/>
<FrameLayout android:layout_width="40px" android:layout_height="40px" android:background="#F00"/>
</com.asolutions.widget.RowLayout>
