[java] Android 용 줄 바꿈 위젯 레이아웃

나는 이것과 매우 유사한 것을 구현했지만 내가 생각하는 것을 사용하여 간격과 패딩을 처리하는 좀 더 표준적인 방법을 사용했습니다. 여러분의 생각을 알려주세요. 귀속없이 자유롭게 재사용 할 수 있습니다.

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;
        }
    }
}

또한 /res/values/attrs.xml 아래에 항목이 필요하며, 아직없는 경우 만들 수 있습니다.

<?xml version="1.0" encoding="utf-8"?>
<resources>
    <declare-styleable name="RowLayout">
        <attr name="android:verticalSpacing" />
        <attr name="android:horizontalSpacing" />
    </declare-styleable>
</resources>

xml 레이아웃에서의 사용법은 다음과 같습니다.

<?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>

답변

    package com.superliminal.android.util;

    import android.content.Context;
    import android.util.AttributeSet;
    import android.view.View;
    import android.view.ViewGroup;


    /**
     * A view container with layout behavior like that of the Swing FlowLayout.
     * Originally from http://nishantvnair.wordpress.com/2010/09/28/flowlayout-in-android/ itself derived from
     * http://stackoverflow.com/questions/549451/line-breaking-widget-layout-for-android
     *
     * @author Melinda Green
     */
    public class FlowLayout extends ViewGroup {
        private final static int PAD_H = 2, PAD_V = 2; // Space between child views.
        private int mHeight;

        public FlowLayout(Context context) {
            super(context);
        }

        public FlowLayout(Context context, AttributeSet attrs) {
            super(context, attrs);
        }

        @Override
        protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {
            assert (MeasureSpec.getMode(widthMeasureSpec) != MeasureSpec.UNSPECIFIED);
            final int width = MeasureSpec.getSize(widthMeasureSpec) - getPaddingLeft() - getPaddingRight();
            int height = MeasureSpec.getSize(heightMeasureSpec) - getPaddingTop() - getPaddingBottom();
            final int count = getChildCount();
            int xpos = getPaddingLeft();
            int ypos = getPaddingTop();
            int childHeightMeasureSpec;
            if(MeasureSpec.getMode(heightMeasureSpec) == MeasureSpec.AT_MOST)
                childHeightMeasureSpec = MeasureSpec.makeMeasureSpec(height, MeasureSpec.AT_MOST);
            else
                childHeightMeasureSpec = MeasureSpec.makeMeasureSpec(0, MeasureSpec.UNSPECIFIED);
            mHeight = 0;
            for(int i = 0; i < count; i++) {
                final View child = getChildAt(i);
                if(child.getVisibility() != GONE) {
                    child.measure(MeasureSpec.makeMeasureSpec(width, MeasureSpec.AT_MOST), childHeightMeasureSpec);
                    final int childw = child.getMeasuredWidth();
                    mHeight = Math.max(mHeight, child.getMeasuredHeight() + PAD_V);
                    if(xpos + childw > width) {
                        xpos = getPaddingLeft();
                        ypos += mHeight;
                    }
                    xpos += childw + PAD_H;
                }
            }
            if(MeasureSpec.getMode(heightMeasureSpec) == MeasureSpec.UNSPECIFIED) {
                height = ypos + mHeight;
            } else if(MeasureSpec.getMode(heightMeasureSpec) == MeasureSpec.AT_MOST) {
                if(ypos + mHeight < height) {
                    height = ypos + mHeight;
                }
            }
            height += 5; // Fudge to avoid clipping bottom of last row.
            setMeasuredDimension(width, height);
        } // end onMeasure()

        @Override
        protected void onLayout(boolean changed, int l, int t, int r, int b) {
            final int width = r - l;
            int xpos = getPaddingLeft();
            int ypos = getPaddingTop();
            for(int i = 0; i < getChildCount(); i++) {
                final View child = getChildAt(i);
                if(child.getVisibility() != GONE) {
                    final int childw = child.getMeasuredWidth();
                    final int childh = child.getMeasuredHeight();
                    if(xpos + childw > width) {
                        xpos = getPaddingLeft();
                        ypos += mHeight;
                    }
                    child.layout(xpos, ypos, xpos + childw, ypos + childh);
                    xpos += childw + PAD_H;
                }
            }
        } // end onLayout()

    }

child.measure(
    MeasureSpec.makeMeasureSpec(width, MeasureSpec.AT_MOST),
    MeasureSpec.makeMeasureSpec(height, MeasureSpec.AT_MOST));

int childHeightMeasureSpec;
if (MeasureSpec.getMode(heightMeasureSpec) == MeasureSpec.AT_MOST) {
    childHeightMeasureSpec =
        MeasureSpec.makeMeasureSpec(height, MeasureSpec.AT_MOST);
}
else {
    childHeightMeasureSpec =
        MeasureSpec.makeMeasureSpec(0, MeasureSpec.UNSPECIFIED);
}

child.measure(MeasureSpec.makeMeasureSpec(width, MeasureSpec.AT_MOST),
    childHeightMeasureSpec);