Java tutorial
/* * Copyright (C) 2010 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.v7.widget; import android.content.Context; import android.content.res.TypedArray; import android.graphics.drawable.Drawable; import android.os.Build; import android.support.annotation.RestrictTo; import android.support.v4.view.ViewCompat; import android.support.v7.appcompat.R; import android.support.v7.view.ActionMode; import android.util.AttributeSet; import android.view.MotionEvent; import android.view.View; import android.view.ViewGroup; import android.widget.FrameLayout; import static android.support.annotation.RestrictTo.Scope.GROUP_ID; /** * This class acts as a container for the action bar view and action mode context views. * It applies special styles as needed to help handle animated transitions between them. * @hide */ @RestrictTo(GROUP_ID) public class ActionBarContainer extends FrameLayout { private boolean mIsTransitioning; private View mTabContainer; private View mActionBarView; private View mContextView; Drawable mBackground; Drawable mStackedBackground; Drawable mSplitBackground; boolean mIsSplit; boolean mIsStacked; private int mHeight; public ActionBarContainer(Context context) { this(context, null); } public ActionBarContainer(Context context, AttributeSet attrs) { super(context, attrs); // Set a transparent background so that we project appropriately. final Drawable bg = Build.VERSION.SDK_INT >= 21 ? new ActionBarBackgroundDrawableV21(this) : new ActionBarBackgroundDrawable(this); ViewCompat.setBackground(this, bg); TypedArray a = context.obtainStyledAttributes(attrs, R.styleable.ActionBar); mBackground = a.getDrawable(R.styleable.ActionBar_background); mStackedBackground = a.getDrawable(R.styleable.ActionBar_backgroundStacked); mHeight = a.getDimensionPixelSize(R.styleable.ActionBar_height, -1); if (getId() == R.id.split_action_bar) { mIsSplit = true; mSplitBackground = a.getDrawable(R.styleable.ActionBar_backgroundSplit); } a.recycle(); setWillNotDraw(mIsSplit ? mSplitBackground == null : mBackground == null && mStackedBackground == null); } @Override public void onFinishInflate() { super.onFinishInflate(); mActionBarView = findViewById(R.id.action_bar); mContextView = findViewById(R.id.action_context_bar); } public void setPrimaryBackground(Drawable bg) { if (mBackground != null) { mBackground.setCallback(null); unscheduleDrawable(mBackground); } mBackground = bg; if (bg != null) { bg.setCallback(this); if (mActionBarView != null) { mBackground.setBounds(mActionBarView.getLeft(), mActionBarView.getTop(), mActionBarView.getRight(), mActionBarView.getBottom()); } } setWillNotDraw(mIsSplit ? mSplitBackground == null : mBackground == null && mStackedBackground == null); invalidate(); } public void setStackedBackground(Drawable bg) { if (mStackedBackground != null) { mStackedBackground.setCallback(null); unscheduleDrawable(mStackedBackground); } mStackedBackground = bg; if (bg != null) { bg.setCallback(this); if ((mIsStacked && mStackedBackground != null)) { mStackedBackground.setBounds(mTabContainer.getLeft(), mTabContainer.getTop(), mTabContainer.getRight(), mTabContainer.getBottom()); } } setWillNotDraw(mIsSplit ? mSplitBackground == null : mBackground == null && mStackedBackground == null); invalidate(); } public void setSplitBackground(Drawable bg) { if (mSplitBackground != null) { mSplitBackground.setCallback(null); unscheduleDrawable(mSplitBackground); } mSplitBackground = bg; if (bg != null) { bg.setCallback(this); if (mIsSplit && mSplitBackground != null) { mSplitBackground.setBounds(0, 0, getMeasuredWidth(), getMeasuredHeight()); } } setWillNotDraw(mIsSplit ? mSplitBackground == null : mBackground == null && mStackedBackground == null); invalidate(); } @Override public void setVisibility(int visibility) { super.setVisibility(visibility); final boolean isVisible = visibility == VISIBLE; if (mBackground != null) mBackground.setVisible(isVisible, false); if (mStackedBackground != null) mStackedBackground.setVisible(isVisible, false); if (mSplitBackground != null) mSplitBackground.setVisible(isVisible, false); } @Override protected boolean verifyDrawable(Drawable who) { return (who == mBackground && !mIsSplit) || (who == mStackedBackground && mIsStacked) || (who == mSplitBackground && mIsSplit) || super.verifyDrawable(who); } @Override protected void drawableStateChanged() { super.drawableStateChanged(); if (mBackground != null && mBackground.isStateful()) { mBackground.setState(getDrawableState()); } if (mStackedBackground != null && mStackedBackground.isStateful()) { mStackedBackground.setState(getDrawableState()); } if (mSplitBackground != null && mSplitBackground.isStateful()) { mSplitBackground.setState(getDrawableState()); } } public void jumpDrawablesToCurrentState() { if (Build.VERSION.SDK_INT >= 11) { super.jumpDrawablesToCurrentState(); if (mBackground != null) { mBackground.jumpToCurrentState(); } if (mStackedBackground != null) { mStackedBackground.jumpToCurrentState(); } if (mSplitBackground != null) { mSplitBackground.jumpToCurrentState(); } } } /** * Set the action bar into a "transitioning" state. While transitioning the bar will block focus * and touch from all of its descendants. This prevents the user from interacting with the bar * while it is animating in or out. * * @param isTransitioning true if the bar is currently transitioning, false otherwise. */ public void setTransitioning(boolean isTransitioning) { mIsTransitioning = isTransitioning; setDescendantFocusability(isTransitioning ? FOCUS_BLOCK_DESCENDANTS : FOCUS_AFTER_DESCENDANTS); } @Override public boolean onInterceptTouchEvent(MotionEvent ev) { return mIsTransitioning || super.onInterceptTouchEvent(ev); } @Override public boolean onTouchEvent(MotionEvent ev) { super.onTouchEvent(ev); // An action bar always eats touch events. return true; } public void setTabContainer(ScrollingTabContainerView tabView) { if (mTabContainer != null) { removeView(mTabContainer); } mTabContainer = tabView; if (tabView != null) { addView(tabView); final ViewGroup.LayoutParams lp = tabView.getLayoutParams(); lp.width = LayoutParams.MATCH_PARENT; lp.height = LayoutParams.WRAP_CONTENT; tabView.setAllowCollapse(false); } } public View getTabContainer() { return mTabContainer; } public android.view.ActionMode startActionModeForChild(View child, android.view.ActionMode.Callback callback) { // No starting an action mode for an action bar child! (Where would it go?) return null; } public android.view.ActionMode startActionModeForChild(View child, android.view.ActionMode.Callback callback, int type) { if (type != android.view.ActionMode.TYPE_PRIMARY) { return super.startActionModeForChild(child, callback, type); } return null; } private boolean isCollapsed(View view) { return view == null || view.getVisibility() == GONE || view.getMeasuredHeight() == 0; } private int getMeasuredHeightWithMargins(View view) { final LayoutParams lp = (LayoutParams) view.getLayoutParams(); return view.getMeasuredHeight() + lp.topMargin + lp.bottomMargin; } @Override public void onMeasure(int widthMeasureSpec, int heightMeasureSpec) { if (mActionBarView == null && MeasureSpec.getMode(heightMeasureSpec) == MeasureSpec.AT_MOST && mHeight >= 0) { heightMeasureSpec = MeasureSpec.makeMeasureSpec( Math.min(mHeight, MeasureSpec.getSize(heightMeasureSpec)), MeasureSpec.AT_MOST); } super.onMeasure(widthMeasureSpec, heightMeasureSpec); if (mActionBarView == null) return; final int mode = MeasureSpec.getMode(heightMeasureSpec); if (mTabContainer != null && mTabContainer.getVisibility() != GONE && mode != MeasureSpec.EXACTLY) { final int topMarginForTabs; if (!isCollapsed(mActionBarView)) { topMarginForTabs = getMeasuredHeightWithMargins(mActionBarView); } else if (!isCollapsed(mContextView)) { topMarginForTabs = getMeasuredHeightWithMargins(mContextView); } else { topMarginForTabs = 0; } final int maxHeight = mode == MeasureSpec.AT_MOST ? MeasureSpec.getSize(heightMeasureSpec) : Integer.MAX_VALUE; setMeasuredDimension(getMeasuredWidth(), Math.min(topMarginForTabs + getMeasuredHeightWithMargins(mTabContainer), maxHeight)); } } @Override public void onLayout(boolean changed, int l, int t, int r, int b) { super.onLayout(changed, l, t, r, b); final View tabContainer = mTabContainer; final boolean hasTabs = tabContainer != null && tabContainer.getVisibility() != GONE; if (tabContainer != null && tabContainer.getVisibility() != GONE) { final int containerHeight = getMeasuredHeight(); final LayoutParams lp = (LayoutParams) tabContainer.getLayoutParams(); final int tabHeight = tabContainer.getMeasuredHeight(); tabContainer.layout(l, containerHeight - tabHeight - lp.bottomMargin, r, containerHeight - lp.bottomMargin); } boolean needsInvalidate = false; if (mIsSplit) { if (mSplitBackground != null) { mSplitBackground.setBounds(0, 0, getMeasuredWidth(), getMeasuredHeight()); needsInvalidate = true; } } else { if (mBackground != null) { if (mActionBarView.getVisibility() == View.VISIBLE) { mBackground.setBounds(mActionBarView.getLeft(), mActionBarView.getTop(), mActionBarView.getRight(), mActionBarView.getBottom()); } else if (mContextView != null && mContextView.getVisibility() == View.VISIBLE) { mBackground.setBounds(mContextView.getLeft(), mContextView.getTop(), mContextView.getRight(), mContextView.getBottom()); } else { mBackground.setBounds(0, 0, 0, 0); } needsInvalidate = true; } mIsStacked = hasTabs; if (hasTabs && mStackedBackground != null) { mStackedBackground.setBounds(tabContainer.getLeft(), tabContainer.getTop(), tabContainer.getRight(), tabContainer.getBottom()); needsInvalidate = true; } } if (needsInvalidate) { invalidate(); } } }