Java tutorial
/* * Copyright (C) 2014 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.support.v7ox.widget; import android.content.Context; import android.graphics.Rect; import android.support.v4ox.view.ViewCompat; import android.util.AttributeSet; import android.util.DisplayMetrics; import android.util.TypedValue; import android.widget.FrameLayout; import static android.view.View.MeasureSpec.AT_MOST; import static android.view.View.MeasureSpec.EXACTLY; import static android.view.View.MeasureSpec.getMode; /** * @hide */ public class ContentFrameLayout extends FrameLayout { public interface OnAttachListener { void onDetachedFromWindow(); void onAttachedFromWindow(); } private TypedValue mMinWidthMajor; private TypedValue mMinWidthMinor; private TypedValue mFixedWidthMajor; private TypedValue mFixedWidthMinor; private TypedValue mFixedHeightMajor; private TypedValue mFixedHeightMinor; private final Rect mDecorPadding; private OnAttachListener mAttachListener; public ContentFrameLayout(Context context) { this(context, null); } public ContentFrameLayout(Context context, AttributeSet attrs) { this(context, attrs, 0); } public ContentFrameLayout(Context context, AttributeSet attrs, int defStyleAttr) { super(context, attrs, defStyleAttr); mDecorPadding = new Rect(); } /** * @hide */ public void dispatchFitSystemWindows(Rect insets) { fitSystemWindows(insets); } public void setAttachListener(OnAttachListener attachListener) { mAttachListener = attachListener; } /** * Notify this view of the window decor view's padding. We use these values when working out * our size for the window size attributes. * * @hide */ public void setDecorPadding(int left, int top, int right, int bottom) { mDecorPadding.set(left, top, right, bottom); if (ViewCompat.isLaidOut(this)) { requestLayout(); } } @Override protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) { final DisplayMetrics metrics = getContext().getResources().getDisplayMetrics(); final boolean isPortrait = metrics.widthPixels < metrics.heightPixels; final int widthMode = getMode(widthMeasureSpec); final int heightMode = getMode(heightMeasureSpec); boolean fixedWidth = false; if (widthMode == AT_MOST) { final TypedValue tvw = isPortrait ? mFixedWidthMinor : mFixedWidthMajor; if (tvw != null && tvw.type != TypedValue.TYPE_NULL) { int w = 0; if (tvw.type == TypedValue.TYPE_DIMENSION) { w = (int) tvw.getDimension(metrics); } else if (tvw.type == TypedValue.TYPE_FRACTION) { w = (int) tvw.getFraction(metrics.widthPixels, metrics.widthPixels); } if (w > 0) { w -= (mDecorPadding.left + mDecorPadding.right); final int widthSize = MeasureSpec.getSize(widthMeasureSpec); widthMeasureSpec = MeasureSpec.makeMeasureSpec(Math.min(w, widthSize), EXACTLY); fixedWidth = true; } } } if (heightMode == AT_MOST) { final TypedValue tvh = isPortrait ? mFixedHeightMajor : mFixedHeightMinor; if (tvh != null && tvh.type != TypedValue.TYPE_NULL) { int h = 0; if (tvh.type == TypedValue.TYPE_DIMENSION) { h = (int) tvh.getDimension(metrics); } else if (tvh.type == TypedValue.TYPE_FRACTION) { h = (int) tvh.getFraction(metrics.heightPixels, metrics.heightPixels); } if (h > 0) { h -= (mDecorPadding.top + mDecorPadding.bottom); final int heightSize = MeasureSpec.getSize(heightMeasureSpec); heightMeasureSpec = MeasureSpec.makeMeasureSpec(Math.min(h, heightSize), EXACTLY); } } } super.onMeasure(widthMeasureSpec, heightMeasureSpec); int width = getMeasuredWidth(); boolean measure = false; widthMeasureSpec = MeasureSpec.makeMeasureSpec(width, EXACTLY); if (!fixedWidth && widthMode == AT_MOST) { final TypedValue tv = isPortrait ? mMinWidthMinor : mMinWidthMajor; if (tv != null && tv.type != TypedValue.TYPE_NULL) { int min = 0; if (tv.type == TypedValue.TYPE_DIMENSION) { min = (int) tv.getDimension(metrics); } else if (tv.type == TypedValue.TYPE_FRACTION) { min = (int) tv.getFraction(metrics.widthPixels, metrics.widthPixels); } if (min > 0) { min -= (mDecorPadding.left + mDecorPadding.right); } if (width < min) { widthMeasureSpec = MeasureSpec.makeMeasureSpec(min, EXACTLY); measure = true; } } } if (measure) { super.onMeasure(widthMeasureSpec, heightMeasureSpec); } } public TypedValue getMinWidthMajor() { if (mMinWidthMajor == null) mMinWidthMajor = new TypedValue(); return mMinWidthMajor; } public TypedValue getMinWidthMinor() { if (mMinWidthMinor == null) mMinWidthMinor = new TypedValue(); return mMinWidthMinor; } public TypedValue getFixedWidthMajor() { if (mFixedWidthMajor == null) mFixedWidthMajor = new TypedValue(); return mFixedWidthMajor; } public TypedValue getFixedWidthMinor() { if (mFixedWidthMinor == null) mFixedWidthMinor = new TypedValue(); return mFixedWidthMinor; } public TypedValue getFixedHeightMajor() { if (mFixedHeightMajor == null) mFixedHeightMajor = new TypedValue(); return mFixedHeightMajor; } public TypedValue getFixedHeightMinor() { if (mFixedHeightMinor == null) mFixedHeightMinor = new TypedValue(); return mFixedHeightMinor; } @Override protected void onAttachedToWindow() { super.onAttachedToWindow(); if (mAttachListener != null) { mAttachListener.onAttachedFromWindow(); } } @Override protected void onDetachedFromWindow() { super.onDetachedFromWindow(); if (mAttachListener != null) { mAttachListener.onDetachedFromWindow(); } } }