AutoLayout 代码解读

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AutoLayout 代码解读

Reference

AutoLayoutConifg

该类的作用是获取屏幕宽高、AndroidManifest.xml中的design_width和design_width字段的值。

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public class AutoLayoutConifg {
    private static AutoLayoutConifg sIntance = new AutoLayoutConifg();
    private static final String KEY_DESIGN_WIDTH = "design_width";
    private static final String KEY_DESIGN_HEIGHT = "design_height";
    private int mScreenWidth;
    private int mScreenHeight;
    private int mDesignWidth;
    private int mDesignHeight;
    private boolean useDeviceSize;
    private AutoLayoutConifg() {
    }
    public static AutoLayoutConifg getInstance() {
        return sIntance;
    }
    public void init(Context context) {
        getMetaData(context);
        int[] screenSize = ScreenUtils.getScreenSize(context, useDeviceSize);
        mScreenWidth = screenSize[0];
        mScreenHeight = screenSize[1];
        L.e("screenWidth = " + mScreenWidth + ", screenHeight = " + mScreenHeight);
    }
    private void getMetaData(Context context) {
        PackageManager packageManager = context.getPackageManager();
        ApplicationInfo applicationInfo;
        try {
            applicationInfo = packageManager.getApplicationInfo(context.getPackageName(), PackageManager.GET_META_DATA);
            if (applicationInfo != null && applicationInfo.metaData != null) {
                mDesignWidth = (int) applicationInfo.metaData.get(KEY_DESIGN_WIDTH);
                mDesignHeight = (int) applicationInfo.metaData.get(KEY_DESIGN_HEIGHT);
            }
        } catch (PackageManager.NameNotFoundException e) {
            throw new RuntimeException("you must set " + KEY_DESIGN_WIDTH + " and " + KEY_DESIGN_HEIGHT + " in your manifest file.", e);
        }
        L.e("designWidth = " + mDesignWidth + ", designHeight = " + mDesignHeight);
    }
    public void checkParams() {
        if (mDesignHeight <= 0 || mDesignWidth <= 0) {
            throw new RuntimeException("you must set " + KEY_DESIGN_WIDTH + " and " + KEY_DESIGN_HEIGHT + " in your manifest file.");
        }
    }
    public AutoLayoutConifg useDeviceSize() {
        useDeviceSize = true;
        return this;
    }
    public int getScreenWidth() {
        return mScreenWidth;
    }
    public int getScreenHeight() {
        return mScreenHeight;
    }
    public int getDesignWidth() {
        return mDesignWidth;
    }
    public int getDesignHeight() {
        return mDesignHeight;
    }
}

init(Context context)

获取屏幕宽高。

getMetaData(Context context)

获取AndroidManifest.xml中位于application节点下的design_width和design_width字段的值。

AutoLayoutHelper

该类的作用是计算属性的值并保存到AutoLayoutInfo对象中，在需要的时候将AutoLayoutInfo对象中值替换给对应的属性。

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public class AutoLayoutHelper {
    private static final String TAG = "AutoLayoutHelper";
    private final ViewGroup mHost;
    private static final int[] LL = new int[]{
            android.R.attr.textSize,
            android.R.attr.padding,
            android.R.attr.paddingLeft,
            android.R.attr.paddingTop,
            android.R.attr.paddingRight,
            android.R.attr.paddingBottom,
            android.R.attr.layout_width,
            android.R.attr.layout_height,
            android.R.attr.layout_margin,
            android.R.attr.layout_marginLeft,
            android.R.attr.layout_marginTop,
            android.R.attr.layout_marginRight,
            android.R.attr.layout_marginBottom,
            android.R.attr.maxWidth,
            android.R.attr.maxHeight,
            android.R.attr.minWidth,
            android.R.attr.minHeight,
            android.R.attr.layout_marginStart,
            android.R.attr.layout_marginEnd,
            android.R.attr.paddingStart,
            android.R.attr.paddingEnd,
    };
    private static final int INDEX_TEXT_SIZE = 0;
    private static final int INDEX_PADDING = 1;
    private static final int INDEX_PADDING_LEFT = 2;
    private static final int INDEX_PADDING_TOP = 3;
    private static final int INDEX_PADDING_RIGHT = 4;
    private static final int INDEX_PADDING_BOTTOM = 5;
    private static final int INDEX_WIDTH = 6;
    private static final int INDEX_HEIGHT = 7;
    private static final int INDEX_MARGIN = 8;
    private static final int INDEX_MARGIN_LEFT = 9;
    private static final int INDEX_MARGIN_TOP = 10;
    private static final int INDEX_MARGIN_RIGHT = 11;
    private static final int INDEX_MARGIN_BOTTOM = 12;
    private static final int INDEX_MAX_WIDTH = 13;
    private static final int INDEX_MAX_HEIGHT = 14;
    private static final int INDEX_MIN_WIDTH = 15;
    private static final int INDEX_MIN_HEIGHT = 16;
    private static final int INDEX_MARGIN_START = 17;
    private static final int INDEX_MARGIN_END = 18;
    private static final int INDEX_PADDING_START = 19;
    private static final int INDEX_PADDING_END = 20;
    public AutoLayoutHelper(ViewGroup host) {
        mHost = host;
        initAutoLayoutConfig(host);
    }
    private void initAutoLayoutConfig(ViewGroup host) {
        if (host != null) {
            AutoLayoutConifg autoLayoutConifg = AutoLayoutConifg.getInstance();
            autoLayoutConifg.init(host.getContext());
        } else {
            Log.e(TAG, "host == null");
        }
    }
    public void adjustChildren() {
        AutoLayoutConifg.getInstance().checkParams();
        for (int i = 0, n = mHost.getChildCount(); i < n; i++) {
            View view = mHost.getChildAt(i);
            ViewGroup.LayoutParams params = view.getLayoutParams();
            if (params instanceof AutoLayoutParams) {
                AutoLayoutInfo info = ((AutoLayoutParams) params).getAutoLayoutInfo();
                if (info != null) {
                    info.fillAttrs(view);
                }
            }
        }
    }
    public static AutoLayoutInfo getAutoLayoutInfo(Context context, AttributeSet attrs) {
        TypedArray a = context.obtainStyledAttributes(attrs, R.styleable.AutoLayout_Layout);
        int baseWidth = a.getInt(R.styleable.AutoLayout_Layout_layout_auto_basewidth, 0);
        int baseHeight = a.getInt(R.styleable.AutoLayout_Layout_layout_auto_baseheight, 0);
        a.recycle();
        AutoLayoutInfo info = new AutoLayoutInfo();
        TypedArray array = context.obtainStyledAttributes(attrs, LL);
        for (int i = 0, n = array.getIndexCount(); i < n; i++) {
            int index = array.getIndex(i);
            if (!DimenUtils.isPxVal(array.peekValue(index))) {
                continue;
            }
            int pxVal;
            try {
                pxVal = array.getDimensionPixelOffset(index, 0);
            } catch (Exception e) {
                e.printStackTrace();
                continue;
            }
            switch (index) {
                case INDEX_TEXT_SIZE:
                    info.addAttr(new TextSizeAttr(pxVal, baseWidth, baseHeight));
                    break;
                case INDEX_PADDING:
                    info.addAttr(new PaddingAttr(pxVal, baseWidth, baseHeight));
                    break;
                case INDEX_PADDING_LEFT:
                case INDEX_PADDING_START:
                    info.addAttr(new PaddingLeftAttr(pxVal, baseWidth, baseHeight));
                    break;
                case INDEX_PADDING_TOP:
                    info.addAttr(new PaddingTopAttr(pxVal, baseWidth, baseHeight));
                    break;
                case INDEX_PADDING_RIGHT:
                case INDEX_PADDING_END:
                    info.addAttr(new PaddingRightAttr(pxVal, baseWidth, baseHeight));
                    break;
                case INDEX_PADDING_BOTTOM:
                    info.addAttr(new PaddingBottomAttr(pxVal, baseWidth, baseHeight));
                    break;
                case INDEX_WIDTH:
                    info.addAttr(new WidthAttr(pxVal, baseWidth, baseHeight));
                    break;
                case INDEX_HEIGHT:
                    info.addAttr(new HeightAttr(pxVal, baseWidth, baseHeight));
                    break;
                case INDEX_MARGIN:
                    info.addAttr(new MarginAttr(pxVal, baseWidth, baseHeight));
                    break;
                case INDEX_MARGIN_LEFT:
                case INDEX_MARGIN_START:
                    info.addAttr(new MarginLeftAttr(pxVal, baseWidth, baseHeight));
                    break;
                case INDEX_MARGIN_TOP:
                    info.addAttr(new MarginTopAttr(pxVal, baseWidth, baseHeight));
                    break;
                case INDEX_MARGIN_RIGHT:
                case INDEX_MARGIN_END:
                    info.addAttr(new MarginRightAttr(pxVal, baseWidth, baseHeight));
                    break;
                case INDEX_MARGIN_BOTTOM:
                    info.addAttr(new MarginBottomAttr(pxVal, baseWidth, baseHeight));
                    break;
                case INDEX_MAX_WIDTH:
                    info.addAttr(new MaxWidthAttr(pxVal, baseWidth, baseHeight));
                    break;
                case INDEX_MAX_HEIGHT:
                    info.addAttr(new MaxHeightAttr(pxVal, baseWidth, baseHeight));
                    break;
                case INDEX_MIN_WIDTH:
                    info.addAttr(new MinWidthAttr(pxVal, baseWidth, baseHeight));
                    break;
                case INDEX_MIN_HEIGHT:
                    info.addAttr(new MinHeightAttr(pxVal, baseWidth, baseHeight));
                    break;
            }
        }
        array.recycle();
        L.e("getAutoLayoutInfo " + info.toString());
        return info;
    }
    public interface AutoLayoutParams {
        AutoLayoutInfo getAutoLayoutInfo();
    }
}

adjustChildren()

遍历子 View，如果其布局参数是AutoLayoutParams，则将计算后的属性的值替换给对应的属性。

getAutoLayoutInfo(Context context, AttributeSet attrs)

遍历属性，重新计算属性的值后保存到AutoLayoutInfo对象中。

AutoLayoutInfo

该类的作用是替换属性的值为计算后的值。

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public class AutoLayoutInfo {
    private List<AutoAttr> autoAttrs = new ArrayList<>();
    public void fillAttrs(View view) {
        for (AutoAttr autoAttr : autoAttrs) {
            autoAttr.apply(view);
        }
    }
    public static AutoLayoutInfo getAttrFromView(View view, int attrs, int base) {
        ViewGroup.LayoutParams params = view.getLayoutParams();
        if (params == null) {
            return null;
        }
        AutoLayoutInfo autoLayoutInfo = new AutoLayoutInfo();
        // width, height
        if ((attrs & Attrs.WIDTH) != 0 && params.width > 0) {
            autoLayoutInfo.addAttr(WidthAttr.generate(params.width, base));
        }
        if ((attrs & Attrs.HEIGHT) != 0 && params.height > 0) {
            autoLayoutInfo.addAttr(HeightAttr.generate(params.height, base));
        }
        // margin
        if (params instanceof ViewGroup.MarginLayoutParams) {
            if ((attrs & Attrs.MARGIN) != 0) {
                autoLayoutInfo.addAttr(MarginLeftAttr.generate(((ViewGroup.MarginLayoutParams) params).leftMargin, base));
                autoLayoutInfo.addAttr(MarginTopAttr.generate(((ViewGroup.MarginLayoutParams) params).topMargin, base));
                autoLayoutInfo.addAttr(MarginRightAttr.generate(((ViewGroup.MarginLayoutParams) params).rightMargin, base));
                autoLayoutInfo.addAttr(MarginBottomAttr.generate(((ViewGroup.MarginLayoutParams) params).bottomMargin, base));
            }
            if ((attrs & Attrs.MARGIN_LEFT) != 0) {
                autoLayoutInfo.addAttr(MarginLeftAttr.generate(((ViewGroup.MarginLayoutParams) params).leftMargin, base));
            }
            if ((attrs & Attrs.MARGIN_TOP) != 0) {
                autoLayoutInfo.addAttr(MarginTopAttr.generate(((ViewGroup.MarginLayoutParams) params).topMargin, base));
            }
            if ((attrs & Attrs.MARGIN_RIGHT) != 0) {
                autoLayoutInfo.addAttr(MarginRightAttr.generate(((ViewGroup.MarginLayoutParams) params).rightMargin, base));
            }
            if ((attrs & Attrs.MARGIN_BOTTOM) != 0) {
                autoLayoutInfo.addAttr(MarginBottomAttr.generate(((ViewGroup.MarginLayoutParams) params).bottomMargin, base));
            }
        }
        // padding
        if ((attrs & Attrs.PADDING) != 0) {
            autoLayoutInfo.addAttr(PaddingLeftAttr.generate(view.getPaddingLeft(), base));
            autoLayoutInfo.addAttr(PaddingTopAttr.generate(view.getPaddingTop(), base));
            autoLayoutInfo.addAttr(PaddingRightAttr.generate(view.getPaddingRight(), base));
            autoLayoutInfo.addAttr(PaddingBottomAttr.generate(view.getPaddingBottom(), base));
        }
        if ((attrs & Attrs.PADDING_LEFT) != 0) {
            autoLayoutInfo.addAttr(MarginLeftAttr.generate(view.getPaddingLeft(), base));
        }
        if ((attrs & Attrs.PADDING_TOP) != 0) {
            autoLayoutInfo.addAttr(MarginTopAttr.generate(view.getPaddingTop(), base));
        }
        if ((attrs & Attrs.PADDING_RIGHT) != 0) {
            autoLayoutInfo.addAttr(MarginRightAttr.generate(view.getPaddingRight(), base));
        }
        if ((attrs & Attrs.PADDING_BOTTOM) != 0) {
            autoLayoutInfo.addAttr(MarginBottomAttr.generate(view.getPaddingBottom(), base));
        }
        // minWidth, maxWidth, minHeight, maxHeight
        if ((attrs & Attrs.MIN_WIDTH) != 0) {
            autoLayoutInfo.addAttr(MinWidthAttr.generate(MinWidthAttr.getMinWidth(view), base));
        }
        if ((attrs & Attrs.MAX_WIDTH) != 0) {
            autoLayoutInfo.addAttr(MaxWidthAttr.generate(MaxWidthAttr.getMaxWidth(view), base));
        }
        if ((attrs & Attrs.MIN_HEIGHT) != 0) {
            autoLayoutInfo.addAttr(MinHeightAttr.generate(MinHeightAttr.getMinHeight(view), base));
        }
        if ((attrs & Attrs.MAX_HEIGHT) != 0) {
            autoLayoutInfo.addAttr(MaxHeightAttr.generate(MaxHeightAttr.getMaxHeight(view), base));
        }
        // textSize
        if (view instanceof TextView) {
            if ((attrs & Attrs.TEXTSIZE) != 0) {
                autoLayoutInfo.addAttr(TextSizeAttr.generate((int) ((TextView) view).getTextSize(), base));
            }
        }
        return autoLayoutInfo;
    }
    public void addAttr(AutoAttr autoAttr) {
        autoAttrs.add(autoAttr);
    }
    @Override
    public String toString() {
        return "AutoLayoutInfo { autoAttrs = " + autoAttrs + " }";
    }
}

getAttrFromView(View view, int attrs, int base)

遍历属性，重新计算属性的值并保存。

fillAttrs(View view)

遍历属性，将属性应用到给定的 View 上。

AutoUtils

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public class AutoUtils {
    /**
     * 会直接将view的LayoutParams上设置的width，height直接进行百分比处理
     *
     * @param view
     */
    public static void auto(View view) {
        autoSize(view);
        autoPadding(view);
        autoMargin(view);
        autoTextSize(view, AutoAttr.BASE_DEFAULT);
    }
    /**
     * @param view
     * @param attrs #Attrs.WIDTH|Attrs.HEIGHT
     * @param base  AutoAttr.BASE_WIDTH|AutoAttr.BASE_HEIGHT|AutoAttr.BASE_DEFAULT
     */
    public static void auto(View view, int attrs, int base) {
        AutoLayoutInfo autoLayoutInfo = AutoLayoutInfo.getAttrFromView(view, attrs, base);
        if (autoLayoutInfo != null) {
            autoLayoutInfo.fillAttrs(view);
        }
    }
    public static void autoTextSize(View view) {
        auto(view, Attrs.TEXTSIZE, AutoAttr.BASE_DEFAULT);
    }
    public static void autoTextSize(View view, int base) {
        auto(view, Attrs.TEXTSIZE, base);
    }
    public static void autoMargin(View view) {
        auto(view, Attrs.MARGIN, AutoAttr.BASE_DEFAULT);
    }
    public static void autoMargin(View view, int base) {
        auto(view, Attrs.MARGIN, base);
    }
    public static void autoPadding(View view) {
        auto(view, Attrs.PADDING, AutoAttr.BASE_DEFAULT);
    }
    public static void autoPadding(View view, int base) {
        auto(view, Attrs.PADDING, base);
    }
    public static void autoSize(View view) {
        auto(view, Attrs.WIDTH | Attrs.HEIGHT, AutoAttr.BASE_DEFAULT);
    }
    public static void autoSize(View view, int base) {
        auto(view, Attrs.WIDTH | Attrs.HEIGHT, base);
    }
    public static boolean autoed(View view) {
        Object tag = view.getTag(R.id.id_tag_autolayout_size);
        if (tag != null) {
            return true;
        }
        view.setTag(R.id.id_tag_autolayout_size, "Just Identify");
        return false;
    }
    public static float getPercentWidth1px() {
        int screenWidth = AutoLayoutConifg.getInstance().getScreenWidth();
        int designWidth = AutoLayoutConifg.getInstance().getDesignWidth();
        return 1.0f * screenWidth / designWidth;
    }
    public static float getPercentHeight1px() {
        int screenHeight = AutoLayoutConifg.getInstance().getScreenHeight();
        int designHeight = AutoLayoutConifg.getInstance().getDesignHeight();
        return 1.0f * screenHeight / designHeight;
    }
    public static int getPercentWidthSize(int val) {
        int screenWidth = AutoLayoutConifg.getInstance().getScreenWidth();
        int designWidth = AutoLayoutConifg.getInstance().getDesignWidth();
        return (int) (val * 1.0f / designWidth * screenWidth);
    }
    public static int getPercentHeightSize(int val) {
        int screenHeight = AutoLayoutConifg.getInstance().getScreenHeight();
        int designHeight = AutoLayoutConifg.getInstance().getDesignHeight();
        return (int) (val * 1.0f / designHeight * screenHeight);
    }
    public static int getPercentWidthSizeBigger(int val) {
        int screenWidth = AutoLayoutConifg.getInstance().getScreenWidth();
        int designWidth = AutoLayoutConifg.getInstance().getDesignWidth();
        int res = val * screenWidth;
        if (res % designWidth == 0) {
            return res / designWidth;
        } else {
            return res / designWidth + 1;
        }
    }
    public static int getPercentHeightSizeBigger(int val) {
        int screenHeight = AutoLayoutConifg.getInstance().getScreenHeight();
        int designHeight = AutoLayoutConifg.getInstance().getDesignHeight();
        int res = val * screenHeight;
        if (res % designHeight == 0) {
            return res / designHeight;
        } else {
            return res / designHeight + 1;
        }
    }
}

getPercentWidth1px()

获取设计图中的1px在当前设备上的宽度。

getPercentHeight1px()

获取设计图中的1px在当前设备上的高度。

getPercentWidthSize(int val)

获取基于宽度计算的设计图中的指定的值在当前设备上的值。

getPercentHeightSize(int val)

获取基于高度计算的设计图中的指定的值在当前设备上的值。

getPercentWidthSizeBigger(int val)

获取基于宽度计算的设计图中的指定的值在当前设备上的值，当为0时，修改为1。

getPercentHeightSizeBigger(int val)

获取基于高度计算的设计图中的指定的值在当前设备上的值，当为0时，修改为1。

AutoAttr

判断是否未设置app:layout_auto_basewidth或app:layout_auto_baseheight，如果未设置，则判断该属性是基于宽度还是基于高度计算，并进行相应的计算；如果设置了基于宽度或高度计算，则进行对应的计算。

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public abstract class AutoAttr {
    public static final int BASE_WIDTH = 1;
    public static final int BASE_HEIGHT = 2;
    public static final int BASE_DEFAULT = 3;
    protected int pxVal;
    protected int baseWidth;
    protected int baseHeight;
    public AutoAttr(int pxVal, int baseWidth, int baseHeight) {
        this.pxVal = pxVal;
        this.baseWidth = baseWidth;
        this.baseHeight = baseHeight;
    }
    public void apply(View view) {
        boolean log = view.getTag() != null && view.getTag().toString().equals("auto");
        if (log) {
            L.e("pxVal = " + pxVal + " ," + getClass().getSimpleName());
        }
        int val;
        if (useDefault()) {
            val = defaultBaseWidth() ? getPercentWidthSize() : getPercentHeightSize();
            if (log) {
                L.e("useDefault val = " + val);
            }
        } else if (baseWidth()) {
            val = getPercentWidthSize();
            if (log) {
                L.e("baseWidth val = " + val);
            }
        } else {
            val = getPercentHeightSize();
            if (log) {
                L.e("baseHeight val = " + val);
            }
        }
        if (val > 0) {
            val = Math.max(val, 1);// for very thin divider
        }
        execute(view, val);
    }
    protected boolean useDefault() {
        return !contains(baseHeight, attrVal()) && !contains(baseWidth, attrVal());
    }
    protected boolean baseWidth() {
        return contains(baseWidth, attrVal());
    }
    protected boolean contains(int baseVal, int flag) {
        return (baseVal & flag) != 0;
    }
    protected int getPercentWidthSize() {
        return AutoUtils.getPercentWidthSizeBigger(pxVal);
    }
    protected int getPercentHeightSize() {
        return AutoUtils.getPercentHeightSizeBigger(pxVal);
    }
    @Override
    public String toString() {
        return "AutoAttr{" +
                "pxVal = " + pxVal +
                ", baseWidth = " + baseWidth() +
                ", defaultBaseWidth = " + defaultBaseWidth() +
                '}';
    }
    protected abstract int attrVal();
    protected abstract boolean defaultBaseWidth();
    protected abstract void execute(View view, int val);
}

attrVal()

该属性在attrs.xml中对应的值。

defaultBaseWidth()

是否默认依赖于宽度进行百分比计算。

execute(View view, int val)

将属性修改后的值替换给对应的属性。

apply(View view)

计算属性的值并将属性修改后的值替换给对应的属性。

useDefault()

判断是否未设置app:layout_auto_basewidth或app:layout_auto_baseheight。

baseWidth()

判断是否设置了app:layout_auto_basewidth。

contains(int baseVal, int flag)

判断是否对应的标志位是否置为了1。

getPercentWidthSize()

基于宽度计算百分比的值。

getPercentHeightSize()

基于高度计算百分比的值。

AutoLayoutActivity

继承AutoLayoutActivity的 Activity 可以使布局实现百分比化。

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public class AutoLayoutActivity extends AppCompatActivity {
    private static final String LAYOUT_LINEARLAYOUT = "LinearLayout";
    private static final String LAYOUT_FRAMELAYOUT = "FrameLayout";
    private static final String LAYOUT_RELATIVELAYOUT = "RelativeLayout";
    @Override
    public View onCreateView(String name, Context context, AttributeSet attrs) {
        View view = null;
        switch (name) {
            case LAYOUT_FRAMELAYOUT:
                view = new AutoFrameLayout(context, attrs);
                break;
            case LAYOUT_LINEARLAYOUT:
                view = new AutoLinearLayout(context, attrs);
                break;
            case LAYOUT_RELATIVELAYOUT:
                view = new AutoRelativeLayout(context, attrs);
                break;
        }
        if (view != null) {
            return view;
        }
        return super.onCreateView(name, context, attrs);
    }
}

onCreateView(String name, Context context, AttributeSet attrs)

替换LinearLayout为AutoLinearLayout，替换FrameLayout为AutoFrameLayout，替换RelativeLayout为AutoRelativeLayout。

AutoRelativeLayout

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public class AutoRelativeLayout extends RelativeLayout {
    private final AutoLayoutHelper mHelper = new AutoLayoutHelper(this);
    public AutoRelativeLayout(Context context) {
        super(context);
    }
    public AutoRelativeLayout(Context context, AttributeSet attrs) {
        super(context, attrs);
    }
    public AutoRelativeLayout(Context context, AttributeSet attrs, int defStyle) {
        super(context, attrs, defStyle);
    }
    @Override
    public LayoutParams generateLayoutParams(AttributeSet attrs) {
        return new LayoutParams(getContext(), attrs);
    }
    @Override
    protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {
        if (!isInEditMode()) {
            mHelper.adjustChildren();
        }
        super.onMeasure(widthMeasureSpec, heightMeasureSpec);
    }
    public static class LayoutParams extends RelativeLayout.LayoutParams implements AutoLayoutHelper.AutoLayoutParams {
        private AutoLayoutInfo mAutoLayoutInfo;
        public LayoutParams(Context c, AttributeSet attrs) {
            super(c, attrs);
            mAutoLayoutInfo = AutoLayoutHelper.getAutoLayoutInfo(c, attrs);
        }
        public LayoutParams(int width, int height) {
            super(width, height);
        }
        public LayoutParams(ViewGroup.LayoutParams source) {
            super(source);
        }
        public LayoutParams(MarginLayoutParams source) {
            super(source);
        }
        @Override
        public AutoLayoutInfo getAutoLayoutInfo() {
            return mAutoLayoutInfo;
        }
    }
}

generateLayoutParams(AttributeSet attrs)

当父容器添加子 View 时调用。返回内部类LayoutParams的对象。

本文标题:AutoLayout 代码解读

文章作者:魏超

发布时间:2018年02月16日 - 16:02

最后更新:2018年02月16日 - 16:02

原始链接:http://www.weichao.io/2018/02/16/AutoLayout-代码解读/

许可协议: 署名-非商业性使用-禁止演绎 4.0 国际 转载请保留原文链接及作者。

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