Java tutorial
/* * Copyright (C) 2012 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 com.aigo.kt03airdemo.ui.view; import android.content.Context; import android.content.res.TypedArray; import android.graphics.Bitmap; import android.graphics.Canvas; import android.graphics.Paint; import android.graphics.PixelFormat; import android.graphics.PorterDuff; import android.graphics.PorterDuffColorFilter; import android.graphics.Rect; import android.graphics.drawable.Drawable; import android.os.Build; import android.os.Parcel; import android.os.Parcelable; import android.support.annotation.NonNull; import android.support.v4.view.MotionEventCompat; import android.support.v4.view.ViewCompat; import android.support.v4.view.ViewPager; import android.support.v4.widget.ViewDragHelper; import android.util.AttributeSet; import android.util.Log; import android.view.MotionEvent; import android.view.View; import android.view.ViewGroup; import java.lang.reflect.Field; import java.lang.reflect.Method; import java.util.ArrayList; public class ResideLayout extends ViewGroup { private static final String TAG = "ResideLayout"; /** * Default size of the overhang for a pane in the open state. * At least this much of a sliding pane will remain visible. * This indicates that there is more content available and provides * a "physical" edge to grab to pull it closed. */ private static final int DEFAULT_OVERHANG_SIZE = 80; // dp; /** * The fade color used for the sliding panel. 0 = no fading. */ private int mSliderFadeColor = 0x99000000; /** * Minimum velocity that will be detected as a fling */ private static final int MIN_FLING_VELOCITY = 400; // dips per second /** * The fade color used for the panel covered by the slider. 0 = no fading. */ private int mCoveredFadeColor = 0xcc000000; /** * The size of the overhang in pixels. * This is the minimum section of the sliding panel that will * be visible in the open state to allow for a closing drag. */ private final int mOverhangSize; /** * True if a panel can slide with the current measurements */ private boolean mCanSlide; /** * The child view that can slide, if any. */ private View mSlideableView; /** * How far the panel is offset from its closed position. * range [0, 1] where 0 = closed, 1 = open. */ private float mSlideOffset; /** * How far the non-sliding panel is parallaxed from its usual position when open. * range [0, 1] */ private float mParallaxOffset; /** * How far in pixels the slideable panel may move. */ private int mSlideRange; /** * A panel view is locked into internal scrolling or another condition that * is preventing a drag. */ private boolean mIsUnableToDrag; /** * Distance in pixels to parallax the fixed pane by when fully closed */ private int mParallaxBy; private float mInitialMotionX; private float mInitialMotionY; private PanelSlideListener mPanelSlideListener; private final ViewDragHelper mDragHelper; /** * Stores whether or not the pane was open the last time it was slideable. * If open/close operations are invoked this state is modified. Used by * instance state save/restore. */ private boolean mPreservedOpenState; private boolean mFirstLayout = true; private final ArrayList<DisableLayerRunnable> mPostedRunnables = new ArrayList<DisableLayerRunnable>(); static final SlidingPanelLayoutImpl IMPL; static { final int deviceVersion = Build.VERSION.SDK_INT; if (deviceVersion >= 17) { IMPL = new SlidingPanelLayoutImplJBMR1(); } else if (deviceVersion >= 16) { IMPL = new SlidingPanelLayoutImplJB(); } else { IMPL = new SlidingPanelLayoutImplBase(); } } /** * Listener for monitoring events about sliding panes. */ public interface PanelSlideListener { /** * Called when a sliding pane's position changes. * @param panel The child view that was moved * @param slideOffset The new offset of this sliding pane within its range, from 0-1 */ public void onPanelSlide(View panel, float slideOffset); /** * Called when a sliding pane becomes slid completely open. The pane may or may not * be interactive at this point depending on how much of the pane is visible. * @param panel The child view that was slid to an open position, revealing other panes */ public void onPanelOpened(View panel); /** * Called when a sliding pane becomes slid completely closed. The pane is now guaranteed * to be interactive. It may now obscure other views in the layout. * @param panel The child view that was slid to a closed position */ public void onPanelClosed(View panel); } public ResideLayout(Context context) { this(context, null); } public ResideLayout(Context context, AttributeSet attrs) { this(context, attrs, 0); } public ResideLayout(Context context, AttributeSet attrs, int defStyle) { super(context, attrs, defStyle); final float density = context.getResources().getDisplayMetrics().density; mOverhangSize = (int) (DEFAULT_OVERHANG_SIZE * density + 0.5f); setWillNotDraw(false); mDragHelper = ViewDragHelper.create(this, 0.5f, new DragHelperCallback()); mDragHelper.setMinVelocity(MIN_FLING_VELOCITY * density); } /** * Set a distance to parallax the lower pane by when the upper pane is in its * fully closed state. The lower pane will scroll between this position and * its fully open state. * * @param parallaxBy Distance to parallax by in pixels */ public void setParallaxDistance(int parallaxBy) { mParallaxBy = parallaxBy; requestLayout(); } /** * @return The distance the lower pane will parallax by when the upper pane is fully closed. * * @see #setParallaxDistance(int) */ public int getParallaxDistance() { return mParallaxBy; } public void setPanelSlideListener(PanelSlideListener listener) { mPanelSlideListener = listener; } void dispatchOnPanelSlide(View panel) { if (mPanelSlideListener != null) { mPanelSlideListener.onPanelSlide(panel, mSlideOffset); } } void dispatchOnPanelOpened(View panel) { if (mPanelSlideListener != null) { mPanelSlideListener.onPanelOpened(panel); } } void dispatchOnPanelClosed(View panel) { if (mPanelSlideListener != null) { mPanelSlideListener.onPanelClosed(panel); } } void updateObscuredViewsVisibility(View panel) { final int startBound = getPaddingLeft(); final int endBound = getWidth() - getPaddingRight(); final int topBound = getPaddingTop(); final int bottomBound = getHeight() - getPaddingBottom(); final int left; final int right; final int top; final int bottom; if (panel != null && viewIsOpaque(panel)) { left = panel.getLeft(); right = panel.getRight(); top = panel.getTop(); bottom = panel.getBottom(); } else { left = right = top = bottom = 0; } for (int i = 0, childCount = getChildCount(); i < childCount; i++) { final View child = getChildAt(i); if (child == panel) { // There are still more children above the panel but they won't be affected. break; } final int clampedChildLeft = Math.max(startBound, child.getLeft()); final int clampedChildTop = Math.max(topBound, child.getTop()); final int clampedChildRight = Math.min(endBound, child.getRight()); final int clampedChildBottom = Math.min(bottomBound, child.getBottom()); final int vis; if (clampedChildLeft >= left && clampedChildTop >= top && clampedChildRight <= right && clampedChildBottom <= bottom) { vis = INVISIBLE; } else { vis = VISIBLE; } child.setVisibility(vis); } } void setAllChildrenVisible() { for (int i = 0, childCount = getChildCount(); i < childCount; i++) { final View child = getChildAt(i); if (child.getVisibility() == INVISIBLE) { child.setVisibility(VISIBLE); } } } private static boolean viewIsOpaque(View v) { if (ViewCompat.isOpaque(v)) return true; // View#isOpaque didn't take all valid opaque scrollbar modes into account // before API 18 (JB-MR2). On newer devices rely solely on isOpaque above and return false // here. On older devices, check the view's background drawable directly as a fallback. if (Build.VERSION.SDK_INT >= 18) return false; final Drawable bg = v.getBackground(); return bg != null && bg.getOpacity() == PixelFormat.OPAQUE; } @Override protected void onAttachedToWindow() { super.onAttachedToWindow(); mFirstLayout = true; } @Override protected void onDetachedFromWindow() { super.onDetachedFromWindow(); mFirstLayout = true; for (final DisableLayerRunnable dlr : mPostedRunnables) { dlr.run(); } mPostedRunnables.clear(); } @Override protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) { int widthMode = MeasureSpec.getMode(widthMeasureSpec); int widthSize = MeasureSpec.getSize(widthMeasureSpec); int heightMode = MeasureSpec.getMode(heightMeasureSpec); int heightSize = MeasureSpec.getSize(heightMeasureSpec); if (widthMode != MeasureSpec.EXACTLY) { if (isInEditMode()) { if (widthMode == MeasureSpec.UNSPECIFIED) { widthSize = 300; } } else { throw new IllegalStateException("Width must have an exact value or MATCH_PARENT"); } } else if (heightMode == MeasureSpec.UNSPECIFIED) { if (isInEditMode()) { if (heightMode == MeasureSpec.UNSPECIFIED) { heightMode = MeasureSpec.AT_MOST; heightSize = 300; } } else { throw new IllegalStateException("Height must not be UNSPECIFIED"); } } int layoutHeight = 0; int maxLayoutHeight = -1; switch (heightMode) { case MeasureSpec.EXACTLY: layoutHeight = maxLayoutHeight = heightSize - getPaddingTop() - getPaddingBottom(); break; case MeasureSpec.AT_MOST: maxLayoutHeight = heightSize - getPaddingTop() - getPaddingBottom(); break; } float weightSum = 0; boolean canSlide = false; final int widthAvailable = widthSize - getPaddingLeft() - getPaddingRight(); int widthRemaining = widthAvailable; final int childCount = getChildCount(); if (childCount > 2) { Log.e(TAG, "onMeasure: More than two child views are not supported."); } // We'll find the current one below. mSlideableView = null; // First pass. Measure based on child LayoutParams width/height. // Weight will incur a second pass. for (int i = 0; i < childCount; i++) { final View child = getChildAt(i); final LayoutParams lp = (LayoutParams) child.getLayoutParams(); if (child.getVisibility() == GONE) { lp.dimWhenOffset = false; continue; } if (lp.weight > 0) { weightSum += lp.weight; // If we have no width, weight is the only contributor to the final size. // Measure this view on the weight pass only. if (lp.width == 0) continue; } int childWidthSpec; final int horizontalMargin = lp.leftMargin + lp.rightMargin; if (lp.width == LayoutParams.WRAP_CONTENT) { childWidthSpec = MeasureSpec.makeMeasureSpec(widthAvailable - horizontalMargin, MeasureSpec.AT_MOST); } else if (lp.width == LayoutParams.MATCH_PARENT) { childWidthSpec = MeasureSpec.makeMeasureSpec(widthAvailable - horizontalMargin, MeasureSpec.EXACTLY); } else { childWidthSpec = MeasureSpec.makeMeasureSpec(lp.width, MeasureSpec.EXACTLY); } int childHeightSpec; if (lp.height == LayoutParams.WRAP_CONTENT) { childHeightSpec = MeasureSpec.makeMeasureSpec(maxLayoutHeight, MeasureSpec.AT_MOST); } else if (lp.height == LayoutParams.MATCH_PARENT) { childHeightSpec = MeasureSpec.makeMeasureSpec(maxLayoutHeight, MeasureSpec.EXACTLY); } else { childHeightSpec = MeasureSpec.makeMeasureSpec(lp.height, MeasureSpec.EXACTLY); } child.measure(childWidthSpec, childHeightSpec); final int childWidth = child.getMeasuredWidth(); final int childHeight = child.getMeasuredHeight(); if (heightMode == MeasureSpec.AT_MOST && childHeight > layoutHeight) { layoutHeight = Math.min(childHeight, maxLayoutHeight); } widthRemaining -= childWidth; canSlide |= lp.slideable = widthRemaining < 0; if (lp.slideable) { mSlideableView = child; } } // Resolve weight and make sure non-sliding panels are smaller than the full screen. if (canSlide || weightSum > 0) { // final int fixedPanelWidthLimit = widthAvailable - mOverhangSize; for (int i = 0; i < childCount; i++) { final View child = getChildAt(i); if (child.getVisibility() == GONE) { continue; } final LayoutParams lp = (LayoutParams) child.getLayoutParams(); if (child.getVisibility() == GONE) { continue; } final boolean skippedFirstPass = lp.width == 0 && lp.weight > 0; final int measuredWidth = skippedFirstPass ? 0 : child.getMeasuredWidth(); if (canSlide && child != mSlideableView) { if (lp.width < 0 && (measuredWidth > widthAvailable || lp.weight > 0)) { // Fixed panels in a sliding configuration should // be clamped to the fixed panel limit. final int childHeightSpec; if (skippedFirstPass) { // Do initial height measurement if we skipped measuring this view // the first time around. if (lp.height == LayoutParams.WRAP_CONTENT) { childHeightSpec = MeasureSpec.makeMeasureSpec(maxLayoutHeight, MeasureSpec.AT_MOST); } else if (lp.height == LayoutParams.MATCH_PARENT) { childHeightSpec = MeasureSpec.makeMeasureSpec(maxLayoutHeight, MeasureSpec.EXACTLY); } else { childHeightSpec = MeasureSpec.makeMeasureSpec(lp.height, MeasureSpec.EXACTLY); } } else { childHeightSpec = MeasureSpec.makeMeasureSpec(child.getMeasuredHeight(), MeasureSpec.EXACTLY); } final int childWidthSpec = MeasureSpec.makeMeasureSpec(widthAvailable, MeasureSpec.EXACTLY); child.measure(childWidthSpec, childHeightSpec); } } else if (lp.weight > 0) { int childHeightSpec; if (lp.width == 0) { // This was skipped the first time; figure out a real height spec. if (lp.height == LayoutParams.WRAP_CONTENT) { childHeightSpec = MeasureSpec.makeMeasureSpec(maxLayoutHeight, MeasureSpec.AT_MOST); } else if (lp.height == LayoutParams.MATCH_PARENT) { childHeightSpec = MeasureSpec.makeMeasureSpec(maxLayoutHeight, MeasureSpec.EXACTLY); } else { childHeightSpec = MeasureSpec.makeMeasureSpec(lp.height, MeasureSpec.EXACTLY); } } else { childHeightSpec = MeasureSpec.makeMeasureSpec(child.getMeasuredHeight(), MeasureSpec.EXACTLY); } if (canSlide) { // Consume available space final int horizontalMargin = lp.leftMargin + lp.rightMargin; final int newWidth = widthAvailable - horizontalMargin; final int childWidthSpec = MeasureSpec.makeMeasureSpec(newWidth, MeasureSpec.EXACTLY); if (measuredWidth != newWidth) { child.measure(childWidthSpec, childHeightSpec); } } else { // Distribute the extra width proportionally similar to LinearLayout final int widthToDistribute = Math.max(0, widthRemaining); final int addedWidth = (int) (lp.weight * widthToDistribute / weightSum); final int childWidthSpec = MeasureSpec.makeMeasureSpec(measuredWidth + addedWidth, MeasureSpec.EXACTLY); child.measure(childWidthSpec, childHeightSpec); } } } } final int measuredWidth = widthSize; final int measuredHeight = layoutHeight + getPaddingTop() + getPaddingBottom(); setMeasuredDimension(measuredWidth, measuredHeight); mCanSlide = canSlide; if (mDragHelper.getViewDragState() != ViewDragHelper.STATE_IDLE && !canSlide) { // Cancel scrolling in progress, it's no longer relevant. mDragHelper.abort(); } } @Override protected void onLayout(boolean changed, int l, int t, int r, int b) { mDragHelper.setEdgeTrackingEnabled(ViewDragHelper.EDGE_LEFT); final int width = r - l; final int paddingStart = getPaddingLeft(); final int paddingEnd = getPaddingRight(); final int paddingTop = getPaddingTop(); final int childCount = getChildCount(); int xStart = paddingStart; int nextXStart = xStart; if (mFirstLayout) { mSlideOffset = mCanSlide && mPreservedOpenState ? 1.f : 0.f; } for (int i = 0; i < childCount; i++) { final View child = getChildAt(i); if (child.getVisibility() == GONE) { continue; } final LayoutParams lp = (LayoutParams) child.getLayoutParams(); final int childWidth = child.getMeasuredWidth(); int offset = 0; if (lp.slideable) { final int margin = lp.leftMargin + lp.rightMargin; final int range = Math.min(nextXStart, width - paddingEnd - mOverhangSize) - xStart - margin; mSlideRange = range; final int lpMargin = lp.leftMargin; lp.dimWhenOffset = xStart + lpMargin + range + childWidth / 2 > width - paddingEnd; final int pos = (int) (range * mSlideOffset); xStart += pos + lpMargin; mSlideOffset = (float) pos / mSlideRange; } else if (mCanSlide && mParallaxBy != 0) { offset = (int) ((1 - mSlideOffset) * mParallaxBy); xStart = nextXStart; } else { xStart = nextXStart; } final int childRight; final int childLeft; childLeft = xStart - offset; childRight = childLeft + childWidth; final int childBottom = paddingTop + child.getMeasuredHeight(); child.layout(childLeft, paddingTop, childRight, childBottom); nextXStart += child.getWidth(); } if (mFirstLayout) { if (mCanSlide) { if (mParallaxBy != 0) { parallaxOtherViews(mSlideOffset); } } updateObscuredViewsVisibility(mSlideableView); } mFirstLayout = false; } @Override protected void onSizeChanged(int w, int h, int oldw, int oldh) { super.onSizeChanged(w, h, oldw, oldh); // Recalculate sliding panes and their details if (w != oldw) { mFirstLayout = true; } } @Override public void requestChildFocus(View child, View focused) { super.requestChildFocus(child, focused); if (!isInTouchMode() && !mCanSlide) { mPreservedOpenState = child == mSlideableView; } } @Override public boolean onInterceptTouchEvent(MotionEvent ev) { final int action = MotionEventCompat.getActionMasked(ev); // Preserve the open state based on the last view that was touched. if (!mCanSlide && action == MotionEvent.ACTION_DOWN && getChildCount() > 1) { // After the first things will be slideable. final View secondChild = getChildAt(1); if (secondChild != null) { mPreservedOpenState = !mDragHelper.isViewUnder(secondChild, (int) ev.getX(), (int) ev.getY()); } } if (!mCanSlide || (mIsUnableToDrag && action != MotionEvent.ACTION_DOWN)) { mDragHelper.cancel(); return super.onInterceptTouchEvent(ev); } if (action == MotionEvent.ACTION_CANCEL || action == MotionEvent.ACTION_UP) { mDragHelper.cancel(); return false; } boolean interceptTap = false; switch (action) { case MotionEvent.ACTION_DOWN: { mIsUnableToDrag = false; final float x = ev.getX(); final float y = ev.getY(); mInitialMotionX = x; mInitialMotionY = y; if (mDragHelper.isViewUnder(mSlideableView, (int) x, (int) y) && isDimmed(mSlideableView)) { interceptTap = true; } break; } case MotionEvent.ACTION_MOVE: { final float x = ev.getX(); final float y = ev.getY(); final float adx = Math.abs(x - mInitialMotionX); final float ady = Math.abs(y - mInitialMotionY); final int slop = mDragHelper.getTouchSlop(); View view = findViewAtPosition(this, (int) x, (int) y); if (adx > slop && ady > adx || view != null) { if (view != null) { Log.d(TAG, "touch on unscrollable view"); } mDragHelper.cancel(); mIsUnableToDrag = true; return false; } } } final boolean interceptForDrag = mDragHelper.shouldInterceptTouchEvent(ev); return interceptForDrag || interceptTap; } private View findViewAtPosition(View parent, int x, int y) { if (parent instanceof ViewPager) { Rect rect = new Rect(); parent.getGlobalVisibleRect(rect); if (rect.contains(x, y)) { return parent; } } else if (parent instanceof ViewGroup) { ViewGroup viewGroup = (ViewGroup) parent; final int length = viewGroup.getChildCount(); for (int i = 0; i < length; i++) { View child = viewGroup.getChildAt(i); View viewAtPosition = findViewAtPosition(child, x, y); if (viewAtPosition != null) { return viewAtPosition; } } return null; } return null; } @Override public boolean onTouchEvent(@NonNull MotionEvent ev) { if (!mCanSlide) { return super.onTouchEvent(ev); } mDragHelper.processTouchEvent(ev); final int action = ev.getAction(); switch (action & MotionEventCompat.ACTION_MASK) { case MotionEvent.ACTION_DOWN: { final float x = ev.getX(); final float y = ev.getY(); mInitialMotionX = x; mInitialMotionY = y; break; } case MotionEvent.ACTION_UP: { if (isDimmed(mSlideableView)) { final float x = ev.getX(); final float y = ev.getY(); final float dx = x - mInitialMotionX; final float dy = y - mInitialMotionY; final int slop = mDragHelper.getTouchSlop(); if (dx * dx + dy * dy < slop * slop && mDragHelper.isViewUnder(mSlideableView, (int) x, (int) y)) { // Taps close a dimmed open pane. closePane(); break; } } break; } } return true; } public boolean closePane() { if (mFirstLayout || smoothSlideTo(0.f)) { mPreservedOpenState = false; return true; } return false; } public boolean openPane() { if (mFirstLayout || smoothSlideTo(1.f)) { mPreservedOpenState = true; return true; } return false; } /** * Check if the layout is completely open. It can be open either because the slider * itself is open revealing the left pane, or if all content fits without sliding. * * @return true if sliding panels are completely open */ public boolean isOpen() { return !mCanSlide || mSlideOffset == 1; } /** * Check if the content in this layout cannot fully fit side by side and therefore * the content pane can be slid back and forth. * * @return true if content in this layout can be slid open and closed */ public boolean isSlideable() { return mCanSlide; } private void onPanelDragged(int newLeft) { if (mSlideableView == null) { // This can happen if we're aborting motion during layout because everything now fits. mSlideOffset = 0; return; } final LayoutParams lp = (LayoutParams) mSlideableView.getLayoutParams(); final int paddingStart = getPaddingLeft(); final int lpMargin = lp.leftMargin; final int startBound = paddingStart + lpMargin; mSlideOffset = (float) (newLeft - startBound) / mSlideRange; parallaxOtherViews(mSlideOffset); if (lp.dimWhenOffset) { dimChildView(mSlideableView, mSlideOffset, mSliderFadeColor); } dispatchOnPanelSlide(mSlideableView); } private void dimChildView(View v, float mag, int fadeColor) { final LayoutParams lp = (LayoutParams) v.getLayoutParams(); if (mag > 0 && fadeColor != 0) { final int baseAlpha = (fadeColor & 0xff000000) >>> 24; int imag = (int) (baseAlpha * mag); int color = imag << 24 | (fadeColor & 0xffffff); if (lp.dimPaint == null) { lp.dimPaint = new Paint(); } lp.dimPaint.setColorFilter(new PorterDuffColorFilter(color, PorterDuff.Mode.SRC_OVER)); if (ViewCompat.getLayerType(v) != ViewCompat.LAYER_TYPE_HARDWARE) { ViewCompat.setLayerType(v, ViewCompat.LAYER_TYPE_HARDWARE, lp.dimPaint); } invalidateChildRegion(v); } else if (ViewCompat.getLayerType(v) != ViewCompat.LAYER_TYPE_NONE) { if (lp.dimPaint != null) { lp.dimPaint.setColorFilter(null); } final DisableLayerRunnable dlr = new DisableLayerRunnable(v); mPostedRunnables.add(dlr); ViewCompat.postOnAnimation(this, dlr); } } @Override protected boolean drawChild(@NonNull Canvas canvas, @NonNull View child, long drawingTime) { final LayoutParams lp = (LayoutParams) child.getLayoutParams(); boolean result; final int save = canvas.save(Canvas.ALL_SAVE_FLAG); if (mCanSlide && !lp.slideable && mSlideableView != null) { // Clip against the slider; no sense drawing what will immediately be covered. canvas.scale(1.2f - 0.2f * mSlideOffset, 1.2f - 0.2f * mSlideOffset, child.getRight(), getHeight() / 2); } else { assert mSlideableView != null; canvas.scale(1 - mSlideOffset / 3, 1 - mSlideOffset / 3, mSlideableView.getLeft(), getHeight() / 2); ViewCompat.setRotationY(child, -10 * mSlideOffset); } if (!lp.slideable && mSlideOffset == 0) { result = true; } else { if (Build.VERSION.SDK_INT >= 11) { // HC result = super.drawChild(canvas, child, drawingTime); } else { if (lp.dimWhenOffset && mSlideOffset > 0) { if (!child.isDrawingCacheEnabled()) { child.setDrawingCacheEnabled(true); } final Bitmap cache = child.getDrawingCache(); if (cache != null) { canvas.drawBitmap(cache, child.getLeft(), child.getTop(), lp.dimPaint); result = false; } else { Log.e(TAG, "drawChild: child view " + child + " returned null drawing cache"); result = super.drawChild(canvas, child, drawingTime); } } else { if (child.isDrawingCacheEnabled()) { child.setDrawingCacheEnabled(false); } result = super.drawChild(canvas, child, drawingTime); } } } canvas.restoreToCount(save); return result; } private void invalidateChildRegion(View v) { IMPL.invalidateChildRegion(this, v); } /** * Smoothly animate mDraggingPane to the target X position within its range. * @param slideOffset position to animate to * */ boolean smoothSlideTo(float slideOffset) { if (!mCanSlide) { // Nothing to do. return false; } final LayoutParams lp = (LayoutParams) mSlideableView.getLayoutParams(); int startBound = getPaddingLeft() + lp.leftMargin; int x = (int) (startBound + slideOffset * mSlideRange); if (mDragHelper.smoothSlideViewTo(mSlideableView, x, mSlideableView.getTop())) { setAllChildrenVisible(); ViewCompat.postInvalidateOnAnimation(this); return true; } return false; } @Override public void computeScroll() { if (mDragHelper.continueSettling(true)) { if (!mCanSlide) { mDragHelper.abort(); return; } ViewCompat.postInvalidateOnAnimation(this); } } private void parallaxOtherViews(float slideOffset) { final LayoutParams slideLp = (LayoutParams) mSlideableView.getLayoutParams(); final boolean dimViews = slideLp.dimWhenOffset && slideLp.leftMargin <= 0; final int childCount = getChildCount(); for (int i = 0; i < childCount; i++) { final View v = getChildAt(i); if (v == mSlideableView) continue; final int oldOffset = (int) ((1 - mParallaxOffset) * mParallaxBy); mParallaxOffset = slideOffset; final int newOffset = (int) ((1 - slideOffset) * mParallaxBy); final int dx = oldOffset - newOffset; v.offsetLeftAndRight(dx); if (dimViews) { dimChildView(v, 1 - mParallaxOffset, mCoveredFadeColor); } } } boolean isDimmed(View child) { if (child == null) { return false; } final LayoutParams lp = (LayoutParams) child.getLayoutParams(); return mCanSlide && lp.dimWhenOffset && mSlideOffset > 0; } @Override protected ViewGroup.LayoutParams generateDefaultLayoutParams() { return new LayoutParams(); } @Override protected ViewGroup.LayoutParams generateLayoutParams(ViewGroup.LayoutParams p) { return p instanceof MarginLayoutParams ? new LayoutParams((MarginLayoutParams) p) : new LayoutParams(p); } @Override protected boolean checkLayoutParams(ViewGroup.LayoutParams p) { return p instanceof LayoutParams && super.checkLayoutParams(p); } @Override public ViewGroup.LayoutParams generateLayoutParams(AttributeSet attrs) { return new LayoutParams(getContext(), attrs); } @Override protected Parcelable onSaveInstanceState() { Parcelable superState = super.onSaveInstanceState(); SavedState ss = new SavedState(superState); ss.isOpen = isSlideable() ? isOpen() : mPreservedOpenState; return ss; } @Override protected void onRestoreInstanceState(Parcelable state) { SavedState ss = (SavedState) state; super.onRestoreInstanceState(ss.getSuperState()); if (ss.isOpen) { openPane(); } else { closePane(); } mPreservedOpenState = ss.isOpen; } private class DragHelperCallback extends ViewDragHelper.Callback { @Override public boolean tryCaptureView(View child, int pointerId) { return !mIsUnableToDrag && ((LayoutParams) child.getLayoutParams()).slideable; } @Override public void onViewDragStateChanged(int state) { if (mDragHelper.getViewDragState() == ViewDragHelper.STATE_IDLE) { if (mSlideOffset == 0) { updateObscuredViewsVisibility(mSlideableView); dispatchOnPanelClosed(mSlideableView); mPreservedOpenState = false; } else { dispatchOnPanelOpened(mSlideableView); mPreservedOpenState = true; } } } @Override public void onViewCaptured(View capturedChild, int activePointerId) { // Make all child views visible in preparation for sliding things around setAllChildrenVisible(); } @Override public void onViewPositionChanged(View changedView, int left, int top, int dx, int dy) { onPanelDragged(left); invalidate(); } @Override public void onViewReleased(View releasedChild, float xvel, float yvel) { final LayoutParams lp = (LayoutParams) releasedChild.getLayoutParams(); int left = getPaddingLeft() + lp.leftMargin; if (xvel > 0 || (xvel == 0 && mSlideOffset > 0.5f)) { left += mSlideRange; } mDragHelper.settleCapturedViewAt(left, releasedChild.getTop()); invalidate(); } @Override public int getViewHorizontalDragRange(View child) { return mSlideRange; } @Override public int clampViewPositionHorizontal(View child, int left, int dx) { final LayoutParams lp = (LayoutParams) mSlideableView.getLayoutParams(); int startBound = getPaddingLeft() + lp.leftMargin; int endBound = startBound + mSlideRange; return Math.min(Math.max(left, startBound), endBound); } @Override public int clampViewPositionVertical(View child, int top, int dy) { // Make sure we never move views vertically. // This could happen if the child has less height than its parent. return child.getTop(); } @Override public void onEdgeDragStarted(int edgeFlags, int pointerId) { mDragHelper.captureChildView(mSlideableView, pointerId); } } public static class LayoutParams extends MarginLayoutParams { private static final int[] ATTRS = new int[] { android.R.attr.layout_weight }; /** * The weighted proportion of how much of the leftover space * this child should consume after measurement. */ public float weight = 0; /** * True if this pane is the slideable pane in the layout. */ boolean slideable; /** * True if this view should be drawn dimmed * when it's been offset from its default position. */ boolean dimWhenOffset; Paint dimPaint; public LayoutParams() { super(MATCH_PARENT, MATCH_PARENT); } public LayoutParams(ViewGroup.LayoutParams source) { super(source); } public LayoutParams(MarginLayoutParams source) { super(source); } public LayoutParams(Context c, AttributeSet attrs) { super(c, attrs); final TypedArray a = c.obtainStyledAttributes(attrs, ATTRS); this.weight = a.getFloat(0, 0); a.recycle(); } } static class SavedState extends BaseSavedState { boolean isOpen; SavedState(Parcelable superState) { super(superState); } private SavedState(Parcel in) { super(in); isOpen = in.readInt() != 0; } @Override public void writeToParcel(@NonNull Parcel out, int flags) { super.writeToParcel(out, flags); out.writeInt(isOpen ? 1 : 0); } public static final Creator<SavedState> CREATOR = new Creator<SavedState>() { public SavedState createFromParcel(Parcel in) { return new SavedState(in); } public SavedState[] newArray(int size) { return new SavedState[size]; } }; } interface SlidingPanelLayoutImpl { void invalidateChildRegion(ResideLayout parent, View child); } static class SlidingPanelLayoutImplBase implements SlidingPanelLayoutImpl { public void invalidateChildRegion(ResideLayout parent, View child) { ViewCompat.postInvalidateOnAnimation(parent, child.getLeft(), child.getTop(), child.getRight(), child.getBottom()); } } static class SlidingPanelLayoutImplJB extends SlidingPanelLayoutImplBase { /* * Private API hacks! Nasty! Bad! * * In Jellybean, some optimizations in the hardware UI renderer * prevent a changed Paint on a View using a hardware layer from having * the intended effect. This twiddles some internal bits on the view to force * it to recreate the display list. */ private Method mGetDisplayList; private Field mRecreateDisplayList; SlidingPanelLayoutImplJB() { try { mGetDisplayList = View.class.getDeclaredMethod("getDisplayList", (Class[]) null); } catch (NoSuchMethodException e) { Log.e(TAG, "Couldn't fetch getDisplayList method; dimming won't work right.", e); } try { mRecreateDisplayList = View.class.getDeclaredField("mRecreateDisplayList"); mRecreateDisplayList.setAccessible(true); } catch (NoSuchFieldException e) { Log.e(TAG, "Couldn't fetch mRecreateDisplayList field; dimming will be slow.", e); } } @Override public void invalidateChildRegion(ResideLayout parent, View child) { if (mGetDisplayList != null && mRecreateDisplayList != null) { try { mRecreateDisplayList.setBoolean(child, true); mGetDisplayList.invoke(child, (Object[]) null); } catch (Exception e) { Log.e(TAG, "Error refreshing display list state", e); } } else { // Slow path. REALLY slow path. Let's hope we don't get here. child.invalidate(); return; } super.invalidateChildRegion(parent, child); } } static class SlidingPanelLayoutImplJBMR1 extends SlidingPanelLayoutImplBase { @Override public void invalidateChildRegion(ResideLayout parent, View child) { ViewCompat.setLayerPaint(child, ((LayoutParams) child.getLayoutParams()).dimPaint); } } private class DisableLayerRunnable implements Runnable { final View mChildView; DisableLayerRunnable(View childView) { mChildView = childView; } @Override public void run() { if (mChildView.getParent() == ResideLayout.this) { ViewCompat.setLayerType(mChildView, ViewCompat.LAYER_TYPE_NONE, null); invalidateChildRegion(mChildView); } mPostedRunnables.remove(this); } } }