Java tutorial
/* * Copyright (C) 2015 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.design.widget; import android.annotation.TargetApi; import android.content.Context; import android.content.res.ColorStateList; import android.content.res.TypedArray; import android.graphics.Canvas; import android.graphics.Rect; import android.graphics.Typeface; import android.graphics.drawable.ColorDrawable; import android.graphics.drawable.Drawable; import android.support.annotation.ColorInt; import android.support.annotation.DrawableRes; import android.support.annotation.IntDef; import android.support.annotation.IntRange; import android.support.annotation.NonNull; import android.support.annotation.Nullable; import android.support.annotation.RequiresApi; import android.support.annotation.RestrictTo; import android.support.annotation.StyleRes; import android.support.design.R; import android.support.v4.content.ContextCompat; import android.support.v4.graphics.drawable.DrawableCompat; import android.support.v4.view.GravityCompat; import android.support.v4.view.ViewCompat; import android.support.v4.view.WindowInsetsCompat; import android.support.v7.widget.Toolbar; import android.text.TextUtils; import android.util.AttributeSet; import android.view.Gravity; import android.view.View; import android.view.ViewGroup; import android.view.ViewParent; import android.widget.FrameLayout; import java.lang.annotation.Retention; import java.lang.annotation.RetentionPolicy; import static android.support.annotation.RestrictTo.Scope.LIBRARY_GROUP; import static android.support.design.widget.MathUtils.constrain; import static android.support.design.widget.ViewUtils.objectEquals; /** * CollapsingToolbarLayout is a wrapper for {@link Toolbar} which implements a collapsing app bar. * It is designed to be used as a direct child of a {@link AppBarLayout}. * CollapsingToolbarLayout contains the following features: * * <h4>Collapsing title</h4> * A title which is larger when the layout is fully visible but collapses and becomes smaller as * the layout is scrolled off screen. You can set the title to display via * {@link #setTitle(CharSequence)}. The title appearance can be tweaked via the * {@code collapsedTextAppearance} and {@code expandedTextAppearance} attributes. * * <h4>Content scrim</h4> * A full-bleed scrim which is show or hidden when the scroll position has hit a certain threshold. * You can change this via {@link #setContentScrim(Drawable)}. * * <h4>Status bar scrim</h4> * A scrim which is show or hidden behind the status bar when the scroll position has hit a certain * threshold. You can change this via {@link #setStatusBarScrim(Drawable)}. This only works * on {@link android.os.Build.VERSION_CODES#LOLLIPOP LOLLIPOP} devices when we set to fit system * windows. * * <h4>Parallax scrolling children</h4> * Child views can opt to be scrolled within this layout in a parallax fashion. * See {@link LayoutParams#COLLAPSE_MODE_PARALLAX} and * {@link LayoutParams#setParallaxMultiplier(float)}. * * <h4>Pinned position children</h4> * Child views can opt to be pinned in space globally. This is useful when implementing a * collapsing as it allows the {@link Toolbar} to be fixed in place even though this layout is * moving. See {@link LayoutParams#COLLAPSE_MODE_PIN}. * * <p><strong>Do not manually add views to the Toolbar at run time</strong>. * We will add a 'dummy view' to the Toolbar which allows us to work out the available space * for the title. This can interfere with any views which you add.</p> * * @attr ref android.support.design.R.styleable#CollapsingToolbarLayout_collapsedTitleTextAppearance * @attr ref android.support.design.R.styleable#CollapsingToolbarLayout_expandedTitleTextAppearance * @attr ref android.support.design.R.styleable#CollapsingToolbarLayout_contentScrim * @attr ref android.support.design.R.styleable#CollapsingToolbarLayout_expandedTitleMargin * @attr ref android.support.design.R.styleable#CollapsingToolbarLayout_expandedTitleMarginStart * @attr ref android.support.design.R.styleable#CollapsingToolbarLayout_expandedTitleMarginEnd * @attr ref android.support.design.R.styleable#CollapsingToolbarLayout_expandedTitleMarginBottom * @attr ref android.support.design.R.styleable#CollapsingToolbarLayout_statusBarScrim * @attr ref android.support.design.R.styleable#CollapsingToolbarLayout_toolbarId */ public class CollapsingToolbarLayout extends FrameLayout { private static final int DEFAULT_SCRIM_ANIMATION_DURATION = 600; private boolean mRefreshToolbar = true; private int mToolbarId; private Toolbar mToolbar; private View mToolbarDirectChild; private View mDummyView; private int mExpandedMarginStart; private int mExpandedMarginTop; private int mExpandedMarginEnd; private int mExpandedMarginBottom; private final Rect mTmpRect = new Rect(); final CollapsingTextHelper mCollapsingTextHelper; private boolean mCollapsingTitleEnabled; private boolean mDrawCollapsingTitle; private Drawable mContentScrim; Drawable mStatusBarScrim; private int mScrimAlpha; private boolean mScrimsAreShown; private ValueAnimatorCompat mScrimAnimator; private long mScrimAnimationDuration; private int mScrimVisibleHeightTrigger = -1; private AppBarLayout.OnOffsetChangedListener mOnOffsetChangedListener; int mCurrentOffset; WindowInsetsCompat mLastInsets; public CollapsingToolbarLayout(Context context) { this(context, null); } public CollapsingToolbarLayout(Context context, AttributeSet attrs) { this(context, attrs, 0); } public CollapsingToolbarLayout(Context context, AttributeSet attrs, int defStyleAttr) { super(context, attrs, defStyleAttr); ThemeUtils.checkAppCompatTheme(context); mCollapsingTextHelper = new CollapsingTextHelper(this); mCollapsingTextHelper.setTextSizeInterpolator(AnimationUtils.DECELERATE_INTERPOLATOR); TypedArray a = context.obtainStyledAttributes(attrs, R.styleable.CollapsingToolbarLayout, defStyleAttr, R.style.Widget_Design_CollapsingToolbar); mCollapsingTextHelper.setExpandedTextGravity(a.getInt( R.styleable.CollapsingToolbarLayout_expandedTitleGravity, GravityCompat.START | Gravity.BOTTOM)); mCollapsingTextHelper .setCollapsedTextGravity(a.getInt(R.styleable.CollapsingToolbarLayout_collapsedTitleGravity, GravityCompat.START | Gravity.CENTER_VERTICAL)); mExpandedMarginStart = mExpandedMarginTop = mExpandedMarginEnd = mExpandedMarginBottom = a .getDimensionPixelSize(R.styleable.CollapsingToolbarLayout_expandedTitleMargin, 0); if (a.hasValue(R.styleable.CollapsingToolbarLayout_expandedTitleMarginStart)) { mExpandedMarginStart = a .getDimensionPixelSize(R.styleable.CollapsingToolbarLayout_expandedTitleMarginStart, 0); } if (a.hasValue(R.styleable.CollapsingToolbarLayout_expandedTitleMarginEnd)) { mExpandedMarginEnd = a.getDimensionPixelSize(R.styleable.CollapsingToolbarLayout_expandedTitleMarginEnd, 0); } if (a.hasValue(R.styleable.CollapsingToolbarLayout_expandedTitleMarginTop)) { mExpandedMarginTop = a.getDimensionPixelSize(R.styleable.CollapsingToolbarLayout_expandedTitleMarginTop, 0); } if (a.hasValue(R.styleable.CollapsingToolbarLayout_expandedTitleMarginBottom)) { mExpandedMarginBottom = a .getDimensionPixelSize(R.styleable.CollapsingToolbarLayout_expandedTitleMarginBottom, 0); } mCollapsingTitleEnabled = a.getBoolean(R.styleable.CollapsingToolbarLayout_titleEnabled, true); setTitle(a.getText(R.styleable.CollapsingToolbarLayout_title)); // First load the default text appearances mCollapsingTextHelper.setExpandedTextAppearance(R.style.TextAppearance_Design_CollapsingToolbar_Expanded); mCollapsingTextHelper.setCollapsedTextAppearance( android.support.v7.appcompat.R.style.TextAppearance_AppCompat_Widget_ActionBar_Title); // Now overlay any custom text appearances if (a.hasValue(R.styleable.CollapsingToolbarLayout_expandedTitleTextAppearance)) { mCollapsingTextHelper.setExpandedTextAppearance( a.getResourceId(R.styleable.CollapsingToolbarLayout_expandedTitleTextAppearance, 0)); } if (a.hasValue(R.styleable.CollapsingToolbarLayout_collapsedTitleTextAppearance)) { mCollapsingTextHelper.setCollapsedTextAppearance( a.getResourceId(R.styleable.CollapsingToolbarLayout_collapsedTitleTextAppearance, 0)); } mScrimVisibleHeightTrigger = a .getDimensionPixelSize(R.styleable.CollapsingToolbarLayout_scrimVisibleHeightTrigger, -1); mScrimAnimationDuration = a.getInt(R.styleable.CollapsingToolbarLayout_scrimAnimationDuration, DEFAULT_SCRIM_ANIMATION_DURATION); setContentScrim(a.getDrawable(R.styleable.CollapsingToolbarLayout_contentScrim)); setStatusBarScrim(a.getDrawable(R.styleable.CollapsingToolbarLayout_statusBarScrim)); mToolbarId = a.getResourceId(R.styleable.CollapsingToolbarLayout_toolbarId, -1); a.recycle(); setWillNotDraw(false); ViewCompat.setOnApplyWindowInsetsListener(this, new android.support.v4.view.OnApplyWindowInsetsListener() { @Override public WindowInsetsCompat onApplyWindowInsets(View v, WindowInsetsCompat insets) { return onWindowInsetChanged(insets); } }); } @Override protected void onAttachedToWindow() { super.onAttachedToWindow(); // Add an OnOffsetChangedListener if possible final ViewParent parent = getParent(); if (parent instanceof AppBarLayout) { // Copy over from the ABL whether we should fit system windows ViewCompat.setFitsSystemWindows(this, ViewCompat.getFitsSystemWindows((View) parent)); if (mOnOffsetChangedListener == null) { mOnOffsetChangedListener = new OffsetUpdateListener(); } ((AppBarLayout) parent).addOnOffsetChangedListener(mOnOffsetChangedListener); // We're attached, so lets request an inset dispatch ViewCompat.requestApplyInsets(this); } } @Override protected void onDetachedFromWindow() { // Remove our OnOffsetChangedListener if possible and it exists final ViewParent parent = getParent(); if (mOnOffsetChangedListener != null && parent instanceof AppBarLayout) { ((AppBarLayout) parent).removeOnOffsetChangedListener(mOnOffsetChangedListener); } super.onDetachedFromWindow(); } WindowInsetsCompat onWindowInsetChanged(final WindowInsetsCompat insets) { WindowInsetsCompat newInsets = null; if (ViewCompat.getFitsSystemWindows(this)) { // If we're set to fit system windows, keep the insets newInsets = insets; } // If our insets have changed, keep them and invalidate the scroll ranges... if (!objectEquals(mLastInsets, newInsets)) { mLastInsets = newInsets; requestLayout(); } // Consume the insets. This is done so that child views with fitSystemWindows=true do not // get the default padding functionality from View return insets.consumeSystemWindowInsets(); } @Override public void draw(Canvas canvas) { super.draw(canvas); // If we don't have a toolbar, the scrim will be not be drawn in drawChild() below. // Instead, we draw it here, before our collapsing text. ensureToolbar(); if (mToolbar == null && mContentScrim != null && mScrimAlpha > 0) { mContentScrim.mutate().setAlpha(mScrimAlpha); mContentScrim.draw(canvas); } // Let the collapsing text helper draw its text if (mCollapsingTitleEnabled && mDrawCollapsingTitle) { mCollapsingTextHelper.draw(canvas); } // Now draw the status bar scrim if (mStatusBarScrim != null && mScrimAlpha > 0) { final int topInset = mLastInsets != null ? mLastInsets.getSystemWindowInsetTop() : 0; if (topInset > 0) { mStatusBarScrim.setBounds(0, -mCurrentOffset, getWidth(), topInset - mCurrentOffset); mStatusBarScrim.mutate().setAlpha(mScrimAlpha); mStatusBarScrim.draw(canvas); } } } @Override protected boolean drawChild(Canvas canvas, View child, long drawingTime) { // This is a little weird. Our scrim needs to be behind the Toolbar (if it is present), // but in front of any other children which are behind it. To do this we intercept the // drawChild() call, and draw our scrim just before the Toolbar is drawn boolean invalidated = false; if (mContentScrim != null && mScrimAlpha > 0 && isToolbarChild(child)) { mContentScrim.mutate().setAlpha(mScrimAlpha); mContentScrim.draw(canvas); invalidated = true; } return super.drawChild(canvas, child, drawingTime) || invalidated; } @Override protected void onSizeChanged(int w, int h, int oldw, int oldh) { super.onSizeChanged(w, h, oldw, oldh); if (mContentScrim != null) { mContentScrim.setBounds(0, 0, w, h); } } private void ensureToolbar() { if (!mRefreshToolbar) { return; } // First clear out the current Toolbar mToolbar = null; mToolbarDirectChild = null; if (mToolbarId != -1) { // If we have an ID set, try and find it and it's direct parent to us mToolbar = (Toolbar) findViewById(mToolbarId); if (mToolbar != null) { mToolbarDirectChild = findDirectChild(mToolbar); } } if (mToolbar == null) { // If we don't have an ID, or couldn't find a Toolbar with the correct ID, try and find // one from our direct children Toolbar toolbar = null; for (int i = 0, count = getChildCount(); i < count; i++) { final View child = getChildAt(i); if (child instanceof Toolbar) { toolbar = (Toolbar) child; break; } } mToolbar = toolbar; } updateDummyView(); mRefreshToolbar = false; } private boolean isToolbarChild(View child) { return (mToolbarDirectChild == null || mToolbarDirectChild == this) ? child == mToolbar : child == mToolbarDirectChild; } /** * Returns the direct child of this layout, which itself is the ancestor of the * given view. */ private View findDirectChild(final View descendant) { View directChild = descendant; for (ViewParent p = descendant.getParent(); p != this && p != null; p = p.getParent()) { if (p instanceof View) { directChild = (View) p; } } return directChild; } private void updateDummyView() { if (!mCollapsingTitleEnabled && mDummyView != null) { // If we have a dummy view and we have our title disabled, remove it from its parent final ViewParent parent = mDummyView.getParent(); if (parent instanceof ViewGroup) { ((ViewGroup) parent).removeView(mDummyView); } } if (mCollapsingTitleEnabled && mToolbar != null) { if (mDummyView == null) { mDummyView = new View(getContext()); } if (mDummyView.getParent() == null) { mToolbar.addView(mDummyView, LayoutParams.MATCH_PARENT, LayoutParams.MATCH_PARENT); } } } @Override protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) { ensureToolbar(); super.onMeasure(widthMeasureSpec, heightMeasureSpec); } @Override protected void onLayout(boolean changed, int left, int top, int right, int bottom) { super.onLayout(changed, left, top, right, bottom); if (mLastInsets != null) { // Shift down any views which are not set to fit system windows final int insetTop = mLastInsets.getSystemWindowInsetTop(); for (int i = 0, z = getChildCount(); i < z; i++) { final View child = getChildAt(i); if (!ViewCompat.getFitsSystemWindows(child)) { if (child.getTop() < insetTop) { // If the child isn't set to fit system windows but is drawing within // the inset offset it down ViewCompat.offsetTopAndBottom(child, insetTop); } } } } // Update the collapsed bounds by getting it's transformed bounds if (mCollapsingTitleEnabled && mDummyView != null) { // We only draw the title if the dummy view is being displayed (Toolbar removes // views if there is no space) mDrawCollapsingTitle = ViewCompat.isAttachedToWindow(mDummyView) && mDummyView.getVisibility() == VISIBLE; if (mDrawCollapsingTitle) { final boolean isRtl = ViewCompat.getLayoutDirection(this) == ViewCompat.LAYOUT_DIRECTION_RTL; // Update the collapsed bounds final int maxOffset = getMaxOffsetForPinChild( mToolbarDirectChild != null ? mToolbarDirectChild : mToolbar); ViewGroupUtils.getDescendantRect(this, mDummyView, mTmpRect); mCollapsingTextHelper.setCollapsedBounds( mTmpRect.left + (isRtl ? mToolbar.getTitleMarginEnd() : mToolbar.getTitleMarginStart()), mTmpRect.top + maxOffset + mToolbar.getTitleMarginTop(), mTmpRect.right + (isRtl ? mToolbar.getTitleMarginStart() : mToolbar.getTitleMarginEnd()), mTmpRect.bottom + maxOffset - mToolbar.getTitleMarginBottom()); // Update the expanded bounds mCollapsingTextHelper.setExpandedBounds(isRtl ? mExpandedMarginEnd : mExpandedMarginStart, mTmpRect.top + mExpandedMarginTop, right - left - (isRtl ? mExpandedMarginStart : mExpandedMarginEnd), bottom - top - mExpandedMarginBottom); // Now recalculate using the new bounds mCollapsingTextHelper.recalculate(); } } // Update our child view offset helpers. This needs to be done after the title has been // setup, so that any Toolbars are in their original position for (int i = 0, z = getChildCount(); i < z; i++) { getViewOffsetHelper(getChildAt(i)).onViewLayout(); } // Finally, set our minimum height to enable proper AppBarLayout collapsing if (mToolbar != null) { if (mCollapsingTitleEnabled && TextUtils.isEmpty(mCollapsingTextHelper.getText())) { // If we do not currently have a title, try and grab it from the Toolbar mCollapsingTextHelper.setText(mToolbar.getTitle()); } if (mToolbarDirectChild == null || mToolbarDirectChild == this) { setMinimumHeight(getHeightWithMargins(mToolbar)); } else { setMinimumHeight(getHeightWithMargins(mToolbarDirectChild)); } } updateScrimVisibility(); } private static int getHeightWithMargins(@NonNull final View view) { final ViewGroup.LayoutParams lp = view.getLayoutParams(); if (lp instanceof MarginLayoutParams) { final MarginLayoutParams mlp = (MarginLayoutParams) lp; return view.getHeight() + mlp.topMargin + mlp.bottomMargin; } return view.getHeight(); } static ViewOffsetHelper getViewOffsetHelper(View view) { ViewOffsetHelper offsetHelper = (ViewOffsetHelper) view.getTag(R.id.view_offset_helper); if (offsetHelper == null) { offsetHelper = new ViewOffsetHelper(view); view.setTag(R.id.view_offset_helper, offsetHelper); } return offsetHelper; } /** * Sets the title to be displayed by this view, if enabled. * * @see #setTitleEnabled(boolean) * @see #getTitle() * * @attr ref R.styleable#CollapsingToolbarLayout_title */ public void setTitle(@Nullable CharSequence title) { mCollapsingTextHelper.setText(title); } /** * Returns the title currently being displayed by this view. If the title is not enabled, then * this will return {@code null}. * * @attr ref R.styleable#CollapsingToolbarLayout_title */ @Nullable public CharSequence getTitle() { return mCollapsingTitleEnabled ? mCollapsingTextHelper.getText() : null; } /** * Sets whether this view should display its own title. * * <p>The title displayed by this view will shrink and grow based on the scroll offset.</p> * * @see #setTitle(CharSequence) * @see #isTitleEnabled() * * @attr ref R.styleable#CollapsingToolbarLayout_titleEnabled */ public void setTitleEnabled(boolean enabled) { if (enabled != mCollapsingTitleEnabled) { mCollapsingTitleEnabled = enabled; updateDummyView(); requestLayout(); } } /** * Returns whether this view is currently displaying its own title. * * @see #setTitleEnabled(boolean) * * @attr ref R.styleable#CollapsingToolbarLayout_titleEnabled */ public boolean isTitleEnabled() { return mCollapsingTitleEnabled; } /** * Set whether the content scrim and/or status bar scrim should be shown or not. Any change * in the vertical scroll may overwrite this value. Any visibility change will be animated if * this view has already been laid out. * * @param shown whether the scrims should be shown * * @see #getStatusBarScrim() * @see #getContentScrim() */ public void setScrimsShown(boolean shown) { setScrimsShown(shown, ViewCompat.isLaidOut(this) && !isInEditMode()); } /** * Set whether the content scrim and/or status bar scrim should be shown or not. Any change * in the vertical scroll may overwrite this value. * * @param shown whether the scrims should be shown * @param animate whether to animate the visibility change * * @see #getStatusBarScrim() * @see #getContentScrim() */ public void setScrimsShown(boolean shown, boolean animate) { if (mScrimsAreShown != shown) { if (animate) { animateScrim(shown ? 0xFF : 0x0); } else { setScrimAlpha(shown ? 0xFF : 0x0); } mScrimsAreShown = shown; } } private void animateScrim(int targetAlpha) { ensureToolbar(); if (mScrimAnimator == null) { mScrimAnimator = ViewUtils.createAnimator(); mScrimAnimator.setDuration(mScrimAnimationDuration); mScrimAnimator .setInterpolator(targetAlpha > mScrimAlpha ? AnimationUtils.FAST_OUT_LINEAR_IN_INTERPOLATOR : AnimationUtils.LINEAR_OUT_SLOW_IN_INTERPOLATOR); mScrimAnimator.addUpdateListener(new ValueAnimatorCompat.AnimatorUpdateListener() { @Override public void onAnimationUpdate(ValueAnimatorCompat animator) { setScrimAlpha(animator.getAnimatedIntValue()); } }); } else if (mScrimAnimator.isRunning()) { mScrimAnimator.cancel(); } mScrimAnimator.setIntValues(mScrimAlpha, targetAlpha); mScrimAnimator.start(); } void setScrimAlpha(int alpha) { if (alpha != mScrimAlpha) { final Drawable contentScrim = mContentScrim; if (contentScrim != null && mToolbar != null) { ViewCompat.postInvalidateOnAnimation(mToolbar); } mScrimAlpha = alpha; ViewCompat.postInvalidateOnAnimation(CollapsingToolbarLayout.this); } } int getScrimAlpha() { return mScrimAlpha; } /** * Set the drawable to use for the content scrim from resources. Providing null will disable * the scrim functionality. * * @param drawable the drawable to display * * @attr ref R.styleable#CollapsingToolbarLayout_contentScrim * @see #getContentScrim() */ public void setContentScrim(@Nullable Drawable drawable) { if (mContentScrim != drawable) { if (mContentScrim != null) { mContentScrim.setCallback(null); } mContentScrim = drawable != null ? drawable.mutate() : null; if (mContentScrim != null) { mContentScrim.setBounds(0, 0, getWidth(), getHeight()); mContentScrim.setCallback(this); mContentScrim.setAlpha(mScrimAlpha); } ViewCompat.postInvalidateOnAnimation(this); } } /** * Set the color to use for the content scrim. * * @param color the color to display * * @attr ref R.styleable#CollapsingToolbarLayout_contentScrim * @see #getContentScrim() */ public void setContentScrimColor(@ColorInt int color) { setContentScrim(new ColorDrawable(color)); } /** * Set the drawable to use for the content scrim from resources. * * @param resId drawable resource id * * @attr ref R.styleable#CollapsingToolbarLayout_contentScrim * @see #getContentScrim() */ public void setContentScrimResource(@DrawableRes int resId) { setContentScrim(ContextCompat.getDrawable(getContext(), resId)); } /** * Returns the drawable which is used for the foreground scrim. * * @attr ref R.styleable#CollapsingToolbarLayout_contentScrim * @see #setContentScrim(Drawable) */ @Nullable public Drawable getContentScrim() { return mContentScrim; } /** * Set the drawable to use for the status bar scrim from resources. * Providing null will disable the scrim functionality. * * <p>This scrim is only shown when we have been given a top system inset.</p> * * @param drawable the drawable to display * * @attr ref R.styleable#CollapsingToolbarLayout_statusBarScrim * @see #getStatusBarScrim() */ public void setStatusBarScrim(@Nullable Drawable drawable) { if (mStatusBarScrim != drawable) { if (mStatusBarScrim != null) { mStatusBarScrim.setCallback(null); } mStatusBarScrim = drawable != null ? drawable.mutate() : null; if (mStatusBarScrim != null) { if (mStatusBarScrim.isStateful()) { mStatusBarScrim.setState(getDrawableState()); } DrawableCompat.setLayoutDirection(mStatusBarScrim, ViewCompat.getLayoutDirection(this)); mStatusBarScrim.setVisible(getVisibility() == VISIBLE, false); mStatusBarScrim.setCallback(this); mStatusBarScrim.setAlpha(mScrimAlpha); } ViewCompat.postInvalidateOnAnimation(this); } } @Override protected void drawableStateChanged() { super.drawableStateChanged(); final int[] state = getDrawableState(); boolean changed = false; Drawable d = mStatusBarScrim; if (d != null && d.isStateful()) { changed |= d.setState(state); } d = mContentScrim; if (d != null && d.isStateful()) { changed |= d.setState(state); } if (mCollapsingTextHelper != null) { changed |= mCollapsingTextHelper.setState(state); } if (changed) { invalidate(); } } @Override protected boolean verifyDrawable(Drawable who) { return super.verifyDrawable(who) || who == mContentScrim || who == mStatusBarScrim; } @Override public void setVisibility(int visibility) { super.setVisibility(visibility); final boolean visible = visibility == VISIBLE; if (mStatusBarScrim != null && mStatusBarScrim.isVisible() != visible) { mStatusBarScrim.setVisible(visible, false); } if (mContentScrim != null && mContentScrim.isVisible() != visible) { mContentScrim.setVisible(visible, false); } } /** * Set the color to use for the status bar scrim. * * <p>This scrim is only shown when we have been given a top system inset.</p> * * @param color the color to display * * @attr ref R.styleable#CollapsingToolbarLayout_statusBarScrim * @see #getStatusBarScrim() */ public void setStatusBarScrimColor(@ColorInt int color) { setStatusBarScrim(new ColorDrawable(color)); } /** * Set the drawable to use for the content scrim from resources. * * @param resId drawable resource id * * @attr ref R.styleable#CollapsingToolbarLayout_statusBarScrim * @see #getStatusBarScrim() */ public void setStatusBarScrimResource(@DrawableRes int resId) { setStatusBarScrim(ContextCompat.getDrawable(getContext(), resId)); } /** * Returns the drawable which is used for the status bar scrim. * * @attr ref R.styleable#CollapsingToolbarLayout_statusBarScrim * @see #setStatusBarScrim(Drawable) */ @Nullable public Drawable getStatusBarScrim() { return mStatusBarScrim; } /** * Sets the text color and size for the collapsed title from the specified * TextAppearance resource. * * @attr ref android.support.design.R.styleable#CollapsingToolbarLayout_collapsedTitleTextAppearance */ public void setCollapsedTitleTextAppearance(@StyleRes int resId) { mCollapsingTextHelper.setCollapsedTextAppearance(resId); } /** * Sets the text color of the collapsed title. * * @param color The new text color in ARGB format */ public void setCollapsedTitleTextColor(@ColorInt int color) { setCollapsedTitleTextColor(ColorStateList.valueOf(color)); } /** * Sets the text colors of the collapsed title. * * @param colors ColorStateList containing the new text colors */ public void setCollapsedTitleTextColor(@NonNull ColorStateList colors) { mCollapsingTextHelper.setCollapsedTextColor(colors); } /** * Sets the horizontal alignment of the collapsed title and the vertical gravity that will * be used when there is extra space in the collapsed bounds beyond what is required for * the title itself. * * @attr ref android.support.design.R.styleable#CollapsingToolbarLayout_collapsedTitleGravity */ public void setCollapsedTitleGravity(int gravity) { mCollapsingTextHelper.setCollapsedTextGravity(gravity); } /** * Returns the horizontal and vertical alignment for title when collapsed. * * @attr ref android.support.design.R.styleable#CollapsingToolbarLayout_collapsedTitleGravity */ public int getCollapsedTitleGravity() { return mCollapsingTextHelper.getCollapsedTextGravity(); } /** * Sets the text color and size for the expanded title from the specified * TextAppearance resource. * * @attr ref android.support.design.R.styleable#CollapsingToolbarLayout_expandedTitleTextAppearance */ public void setExpandedTitleTextAppearance(@StyleRes int resId) { mCollapsingTextHelper.setExpandedTextAppearance(resId); } /** * Sets the text color of the expanded title. * * @param color The new text color in ARGB format */ public void setExpandedTitleColor(@ColorInt int color) { setExpandedTitleTextColor(ColorStateList.valueOf(color)); } /** * Sets the text colors of the expanded title. * * @param colors ColorStateList containing the new text colors */ public void setExpandedTitleTextColor(@NonNull ColorStateList colors) { mCollapsingTextHelper.setExpandedTextColor(colors); } /** * Sets the horizontal alignment of the expanded title and the vertical gravity that will * be used when there is extra space in the expanded bounds beyond what is required for * the title itself. * * @attr ref android.support.design.R.styleable#CollapsingToolbarLayout_expandedTitleGravity */ public void setExpandedTitleGravity(int gravity) { mCollapsingTextHelper.setExpandedTextGravity(gravity); } /** * Returns the horizontal and vertical alignment for title when expanded. * * @attr ref android.support.design.R.styleable#CollapsingToolbarLayout_expandedTitleGravity */ public int getExpandedTitleGravity() { return mCollapsingTextHelper.getExpandedTextGravity(); } /** * Set the typeface to use for the collapsed title. * * @param typeface typeface to use, or {@code null} to use the default. */ public void setCollapsedTitleTypeface(@Nullable Typeface typeface) { mCollapsingTextHelper.setCollapsedTypeface(typeface); } /** * Returns the typeface used for the collapsed title. */ @NonNull public Typeface getCollapsedTitleTypeface() { return mCollapsingTextHelper.getCollapsedTypeface(); } /** * Set the typeface to use for the expanded title. * * @param typeface typeface to use, or {@code null} to use the default. */ public void setExpandedTitleTypeface(@Nullable Typeface typeface) { mCollapsingTextHelper.setExpandedTypeface(typeface); } /** * Returns the typeface used for the expanded title. */ @NonNull public Typeface getExpandedTitleTypeface() { return mCollapsingTextHelper.getExpandedTypeface(); } /** * Sets the expanded title margins. * * @param start the starting title margin in pixels * @param top the top title margin in pixels * @param end the ending title margin in pixels * @param bottom the bottom title margin in pixels * * @see #getExpandedTitleMarginStart() * @see #getExpandedTitleMarginTop() * @see #getExpandedTitleMarginEnd() * @see #getExpandedTitleMarginBottom() * @attr ref android.support.design.R.styleable#CollapsingToolbarLayout_expandedTitleMargin */ public void setExpandedTitleMargin(int start, int top, int end, int bottom) { mExpandedMarginStart = start; mExpandedMarginTop = top; mExpandedMarginEnd = end; mExpandedMarginBottom = bottom; requestLayout(); } /** * @return the starting expanded title margin in pixels * * @see #setExpandedTitleMarginStart(int) * @attr ref android.support.design.R.styleable#CollapsingToolbarLayout_expandedTitleMarginStart */ public int getExpandedTitleMarginStart() { return mExpandedMarginStart; } /** * Sets the starting expanded title margin in pixels. * * @param margin the starting title margin in pixels * @see #getExpandedTitleMarginStart() * @attr ref android.support.design.R.styleable#CollapsingToolbarLayout_expandedTitleMarginStart */ public void setExpandedTitleMarginStart(int margin) { mExpandedMarginStart = margin; requestLayout(); } /** * @return the top expanded title margin in pixels * @see #setExpandedTitleMarginTop(int) * @attr ref android.support.design.R.styleable#CollapsingToolbarLayout_expandedTitleMarginTop */ public int getExpandedTitleMarginTop() { return mExpandedMarginTop; } /** * Sets the top expanded title margin in pixels. * * @param margin the top title margin in pixels * @see #getExpandedTitleMarginTop() * @attr ref android.support.design.R.styleable#CollapsingToolbarLayout_expandedTitleMarginTop */ public void setExpandedTitleMarginTop(int margin) { mExpandedMarginTop = margin; requestLayout(); } /** * @return the ending expanded title margin in pixels * @see #setExpandedTitleMarginEnd(int) * @attr ref android.support.design.R.styleable#CollapsingToolbarLayout_expandedTitleMarginEnd */ public int getExpandedTitleMarginEnd() { return mExpandedMarginEnd; } /** * Sets the ending expanded title margin in pixels. * * @param margin the ending title margin in pixels * @see #getExpandedTitleMarginEnd() * @attr ref android.support.design.R.styleable#CollapsingToolbarLayout_expandedTitleMarginEnd */ public void setExpandedTitleMarginEnd(int margin) { mExpandedMarginEnd = margin; requestLayout(); } /** * @return the bottom expanded title margin in pixels * @see #setExpandedTitleMarginBottom(int) * @attr ref android.support.design.R.styleable#CollapsingToolbarLayout_expandedTitleMarginBottom */ public int getExpandedTitleMarginBottom() { return mExpandedMarginBottom; } /** * Sets the bottom expanded title margin in pixels. * * @param margin the bottom title margin in pixels * @see #getExpandedTitleMarginBottom() * @attr ref android.support.design.R.styleable#CollapsingToolbarLayout_expandedTitleMarginBottom */ public void setExpandedTitleMarginBottom(int margin) { mExpandedMarginBottom = margin; requestLayout(); } /** * Set the amount of visible height in pixels used to define when to trigger a scrim * visibility change. * * <p>If the visible height of this view is less than the given value, the scrims will be * made visible, otherwise they are hidden.</p> * * @param height value in pixels used to define when to trigger a scrim visibility change * * @attr ref android.support.design.R.styleable#CollapsingToolbarLayout_scrimVisibleHeightTrigger */ public void setScrimVisibleHeightTrigger(@IntRange(from = 0) final int height) { if (mScrimVisibleHeightTrigger != height) { mScrimVisibleHeightTrigger = height; // Update the scrim visibility updateScrimVisibility(); } } /** * Returns the amount of visible height in pixels used to define when to trigger a scrim * visibility change. * * @see #setScrimVisibleHeightTrigger(int) */ public int getScrimVisibleHeightTrigger() { if (mScrimVisibleHeightTrigger >= 0) { // If we have one explicitly set, return it return mScrimVisibleHeightTrigger; } // Otherwise we'll use the default computed value final int insetTop = mLastInsets != null ? mLastInsets.getSystemWindowInsetTop() : 0; final int minHeight = ViewCompat.getMinimumHeight(this); if (minHeight > 0) { // If we have a minHeight set, lets use 2 * minHeight (capped at our height) return Math.min((minHeight * 2) + insetTop, getHeight()); } // If we reach here then we don't have a min height set. Instead we'll take a // guess at 1/3 of our height being visible return getHeight() / 3; } /** * Set the duration used for scrim visibility animations. * * @param duration the duration to use in milliseconds * * @attr ref android.support.design.R.styleable#CollapsingToolbarLayout_scrimAnimationDuration */ public void setScrimAnimationDuration(@IntRange(from = 0) final long duration) { mScrimAnimationDuration = duration; } /** * Returns the duration in milliseconds used for scrim visibility animations. */ public long getScrimAnimationDuration() { return mScrimAnimationDuration; } @Override protected boolean checkLayoutParams(ViewGroup.LayoutParams p) { return p instanceof LayoutParams; } @Override protected LayoutParams generateDefaultLayoutParams() { return new LayoutParams(LayoutParams.MATCH_PARENT, LayoutParams.MATCH_PARENT); } @Override public FrameLayout.LayoutParams generateLayoutParams(AttributeSet attrs) { return new LayoutParams(getContext(), attrs); } @Override protected FrameLayout.LayoutParams generateLayoutParams(ViewGroup.LayoutParams p) { return new LayoutParams(p); } public static class LayoutParams extends FrameLayout.LayoutParams { private static final float DEFAULT_PARALLAX_MULTIPLIER = 0.5f; /** @hide */ @RestrictTo(LIBRARY_GROUP) @IntDef({ COLLAPSE_MODE_OFF, COLLAPSE_MODE_PIN, COLLAPSE_MODE_PARALLAX }) @Retention(RetentionPolicy.SOURCE) @interface CollapseMode { } /** * The view will act as normal with no collapsing behavior. */ public static final int COLLAPSE_MODE_OFF = 0; /** * The view will pin in place until it reaches the bottom of the * {@link CollapsingToolbarLayout}. */ public static final int COLLAPSE_MODE_PIN = 1; /** * The view will scroll in a parallax fashion. See {@link #setParallaxMultiplier(float)} * to change the multiplier used. */ public static final int COLLAPSE_MODE_PARALLAX = 2; int mCollapseMode = COLLAPSE_MODE_OFF; float mParallaxMult = DEFAULT_PARALLAX_MULTIPLIER; public LayoutParams(Context c, AttributeSet attrs) { super(c, attrs); TypedArray a = c.obtainStyledAttributes(attrs, R.styleable.CollapsingToolbarLayout_Layout); mCollapseMode = a.getInt(R.styleable.CollapsingToolbarLayout_Layout_layout_collapseMode, COLLAPSE_MODE_OFF); setParallaxMultiplier( a.getFloat(R.styleable.CollapsingToolbarLayout_Layout_layout_collapseParallaxMultiplier, DEFAULT_PARALLAX_MULTIPLIER)); a.recycle(); } public LayoutParams(int width, int height) { super(width, height); } public LayoutParams(int width, int height, int gravity) { super(width, height, gravity); } public LayoutParams(ViewGroup.LayoutParams p) { super(p); } public LayoutParams(MarginLayoutParams source) { super(source); } @RequiresApi(19) @TargetApi(19) public LayoutParams(FrameLayout.LayoutParams source) { // The copy constructor called here only exists on API 19+. super(source); } /** * Set the collapse mode. * * @param collapseMode one of {@link #COLLAPSE_MODE_OFF}, {@link #COLLAPSE_MODE_PIN} * or {@link #COLLAPSE_MODE_PARALLAX}. */ public void setCollapseMode(@CollapseMode int collapseMode) { mCollapseMode = collapseMode; } /** * Returns the requested collapse mode. * * @return the current mode. One of {@link #COLLAPSE_MODE_OFF}, {@link #COLLAPSE_MODE_PIN} * or {@link #COLLAPSE_MODE_PARALLAX}. */ @CollapseMode public int getCollapseMode() { return mCollapseMode; } /** * Set the parallax scroll multiplier used in conjunction with * {@link #COLLAPSE_MODE_PARALLAX}. A value of {@code 0.0} indicates no movement at all, * {@code 1.0f} indicates normal scroll movement. * * @param multiplier the multiplier. * * @see #getParallaxMultiplier() */ public void setParallaxMultiplier(float multiplier) { mParallaxMult = multiplier; } /** * Returns the parallax scroll multiplier used in conjunction with * {@link #COLLAPSE_MODE_PARALLAX}. * * @see #setParallaxMultiplier(float) */ public float getParallaxMultiplier() { return mParallaxMult; } } /** * Show or hide the scrims if needed */ final void updateScrimVisibility() { if (mContentScrim != null || mStatusBarScrim != null) { setScrimsShown(getHeight() + mCurrentOffset < getScrimVisibleHeightTrigger()); } } final int getMaxOffsetForPinChild(View child) { final ViewOffsetHelper offsetHelper = getViewOffsetHelper(child); final LayoutParams lp = (LayoutParams) child.getLayoutParams(); return getHeight() - offsetHelper.getLayoutTop() - child.getHeight() - lp.bottomMargin; } private class OffsetUpdateListener implements AppBarLayout.OnOffsetChangedListener { OffsetUpdateListener() { } @Override public void onOffsetChanged(AppBarLayout layout, int verticalOffset) { mCurrentOffset = verticalOffset; final int insetTop = mLastInsets != null ? mLastInsets.getSystemWindowInsetTop() : 0; for (int i = 0, z = getChildCount(); i < z; i++) { final View child = getChildAt(i); final LayoutParams lp = (LayoutParams) child.getLayoutParams(); final ViewOffsetHelper offsetHelper = getViewOffsetHelper(child); switch (lp.mCollapseMode) { case LayoutParams.COLLAPSE_MODE_PIN: offsetHelper .setTopAndBottomOffset(constrain(-verticalOffset, 0, getMaxOffsetForPinChild(child))); break; case LayoutParams.COLLAPSE_MODE_PARALLAX: offsetHelper.setTopAndBottomOffset(Math.round(-verticalOffset * lp.mParallaxMult)); break; } } // Show or hide the scrims if needed updateScrimVisibility(); if (mStatusBarScrim != null && insetTop > 0) { ViewCompat.postInvalidateOnAnimation(CollapsingToolbarLayout.this); } // Update the collapsing text's fraction final int expandRange = getHeight() - ViewCompat.getMinimumHeight(CollapsingToolbarLayout.this) - insetTop; mCollapsingTextHelper.setExpansionFraction(Math.abs(verticalOffset) / (float) expandRange); } } }