content: /*
   * Copyright (C) 2011 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.lb.launcher;
  
  import com.lb.launcher.R;
  import android.animation.ObjectAnimator;
  import android.animation.PropertyValuesHolder;
  import android.content.Context;
  import android.graphics.Canvas;
  import android.util.AttributeSet;
  import android.util.Pair;
  import android.view.View;
  import android.view.ViewParent;
  
  public class FocusIndicatorView extends View implements View.OnFocusChangeListener {
  
      // It can be any number >0. The view is resized using scaleX and scaleY.
      static final int DEFAULT_LAYOUT_SIZE = 100;
      private static final float MIN_VISIBLE_ALPHA = 0.2f;
      private static final long ANIM_DURATION = 150;
  
      private static final int[] sTempPos = new int[2];
      private static final int[] sTempShift = new int[2];
  
      private final int[] mIndicatorPos = new int[2];
      private final int[] mTargetViewPos = new int[2];
  
      private ObjectAnimator mCurrentAnimation;
      private ViewAnimState mTargetState;
  
      private View mLastFocusedView;
      private boolean mInitiated;
  
      private Pair<View, Boolean> mPendingCall;
  
      public FocusIndicatorView(Context context) {
          this(context, null);
      }
  
      public FocusIndicatorView(Context context, AttributeSet attrs) {
          super(context, attrs);
          setAlpha(0);
          setBackgroundColor(getResources().getColor(R.color.focused_background));
      }
  
      @Override
      protected void onSizeChanged(int w, int h, int oldw, int oldh) {
          super.onSizeChanged(w, h, oldw, oldh);
  
          // Redraw if it is already showing. This avoids a bug where the height changes by a small
          // amount on connecting/disconnecting a bluetooth keyboard.
          if (mLastFocusedView != null) {
              mPendingCall = Pair.create(mLastFocusedView, Boolean.TRUE);
              invalidate();
          }
      }
  
      @Override
      public void onFocusChange(View v, boolean hasFocus) {
          mPendingCall = null;
          if (!mInitiated && (getWidth() == 0)) {
              // View not yet laid out. Wait until the view is ready to be drawn, so that be can
              // get the location on screen.
              mPendingCall = Pair.create(v, hasFocus);
              invalidate();
              return;
          }
  
          if (!mInitiated) {
              getLocationRelativeToParentPagedView(this, mIndicatorPos);
              mInitiated = true;
          }
  
          if (hasFocus) {
              int indicatorWidth = getWidth();
              int indicatorHeight = getHeight();
  
              endCurrentAnimation();
              ViewAnimState nextState = new ViewAnimState();
              nextState.scaleX = v.getScaleX() * v.getWidth() / indicatorWidth;
              nextState.scaleY = v.getScaleY() * v.getHeight() / indicatorHeight;
  
              getLocationRelativeToParentPagedView(v, mTargetViewPos);
              nextState.x = mTargetViewPos[0] - mIndicatorPos[0] - (1 - nextState.scaleX) * indicatorWidth / 2;
              nextState.y = mTargetViewPos[1] - mIndicatorPos[1] - (1 - nextState.scaleY) * indicatorHeight / 2;
  
              if (getAlpha() > MIN_VISIBLE_ALPHA) {
                  mTargetState = nextState;
                  mCurrentAnimation = LauncherAnimUtils.ofPropertyValuesHolder(this,
                          PropertyValuesHolder.ofFloat(View.ALPHA, 1),
                          PropertyValuesHolder.ofFloat(View.TRANSLATION_X, mTargetState.x),
                          PropertyValuesHolder.ofFloat(View.TRANSLATION_Y, mTargetState.y),
                          PropertyValuesHolder.ofFloat(View.SCALE_X, mTargetState.scaleX),
                          PropertyValuesHolder.ofFloat(View.SCALE_Y, mTargetState.scaleY));
              } else {
                  applyState(nextState);
                  mCurrentAnimation = LauncherAnimUtils.ofPropertyValuesHolder(this,
                          PropertyValuesHolder.ofFloat(View.ALPHA, 1));
              }
              mLastFocusedView = v;
          } else {
              if (mLastFocusedView == v) {
                  mLastFocusedView = null;
                  endCurrentAnimation();
                  mCurrentAnimation = LauncherAnimUtils.ofPropertyValuesHolder(this,
                          PropertyValuesHolder.ofFloat(View.ALPHA, 0));
              }
          }
          if (mCurrentAnimation != null) {
              mCurrentAnimation.setDuration(ANIM_DURATION).start();
          }
      }
  
      private void endCurrentAnimation() {
          if (mCurrentAnimation != null) {
              mCurrentAnimation.cancel();
              mCurrentAnimation = null;
          }
          if (mTargetState != null) {
              applyState(mTargetState);
              mTargetState = null;
          }
      }
  
      private void applyState(ViewAnimState state) {
          setTranslationX(state.x);
          setTranslationY(state.y);
          setScaleX(state.scaleX);
          setScaleY(state.scaleY);
      }
  
      @Override
      protected void onDraw(Canvas canvas) {
          if (mPendingCall != null) {
              onFocusChange(mPendingCall.first, mPendingCall.second);
          }
      }
  
      /**
       * Gets the location of a view relative in the window, off-setting any shift due to
       * page view scroll
       */
      private static void getLocationRelativeToParentPagedView(View v, int[] pos) {
          getPagedViewScrollShift(v, sTempShift);
          v.getLocationInWindow(sTempPos);
          pos[0] = sTempPos[0] + sTempShift[0];
          pos[1] = sTempPos[1] + sTempShift[1];
      }
  
      private static void getPagedViewScrollShift(View child, int[] shift) {
          ViewParent parent = child.getParent();
          if (parent instanceof PagedView) {
              View parentView = (View) parent;
              child.getLocationInWindow(sTempPos);
              shift[0] = parentView.getPaddingLeft() - sTempPos[0];
              shift[1] = -(int) child.getTranslationY();
          } else if (parent instanceof View) {
              getPagedViewScrollShift((View) parent, shift);
          } else {
              shift[0] = shift[1] = 0;
          }
      }
  
      private static final class ViewAnimState {
          float x, y, scaleX, scaleY;
      }
  }
  