src/com/android/contacts/detail/ContactDetailFragmentCarousel.java - platform/packages/apps/Contacts - Git at Google

 /*
  * 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.android.contacts.detail;

 import android.content.Context;
 import android.util.AttributeSet;
 import android.view.LayoutInflater;
 import android.view.MotionEvent;
 import android.view.View;
 import android.view.View.OnTouchListener;
 import android.view.ViewPropertyAnimator;
 import android.widget.HorizontalScrollView;

 import com.android.contacts.R;
 import com.android.contacts.widget.FrameLayoutWithOverlay;

 /**
  * This is a horizontally scrolling carousel with 2 fragments: one to see info about the contact and
  * one to see updates from the contact. Depending on the scroll position and user selection of which
  * fragment to currently view, the touch interceptors over each fragment are configured accordingly.
  */
 public class ContactDetailFragmentCarousel extends HorizontalScrollView implements OnTouchListener {

     private static final String TAG = ContactDetailFragmentCarousel.class.getSimpleName();

     /**
      * Number of pixels that this view can be scrolled horizontally.
      */
     private int mAllowedHorizontalScrollLength = Integer.MIN_VALUE;

     /**
      * Minimum X scroll position that must be surpassed (if the user is on the "about" page of the
      * contact card), in order for this view to automatically snap to the "updates" page.
      */
     private int mLowerThreshold = Integer.MIN_VALUE;

     /**
      * Maximum X scroll position (if the user is on the "updates" page of the contact card), below
      * which this view will automatically snap to the "about" page.
      */
     private int mUpperThreshold = Integer.MIN_VALUE;

     /**
      * Minimum width of a fragment (if there is more than 1 fragment in the carousel, then this is
      * the width of one of the fragments).
      */
     private int mMinFragmentWidth = Integer.MIN_VALUE;

     /**
      * Fragment width (if there are 1+ fragments in the carousel) as defined as a fraction of the
      * screen width.
      */
     private static final float FRAGMENT_WIDTH_SCREEN_WIDTH_FRACTION = 0.85f;

     private static final int ABOUT_PAGE = 0;
     private static final int UPDATES_PAGE = 1;

     private static final int MAX_FRAGMENT_VIEW_COUNT = 2;

     private boolean mEnableSwipe;

     private int mCurrentPage = ABOUT_PAGE;
     private int mLastScrollPosition;

     private FrameLayoutWithOverlay mAboutFragment;
     private FrameLayoutWithOverlay mUpdatesFragment;

     public ContactDetailFragmentCarousel(Context context) {
         this(context, null);
     }

     public ContactDetailFragmentCarousel(Context context, AttributeSet attrs) {
         this(context, attrs, 0);
     }

     public ContactDetailFragmentCarousel(Context context, AttributeSet attrs, int defStyle) {
         super(context, attrs, defStyle);

         final LayoutInflater inflater =
                 (LayoutInflater) mContext.getSystemService(Context.LAYOUT_INFLATER_SERVICE);
         inflater.inflate(R.layout.contact_detail_fragment_carousel, this);

         setOnTouchListener(this);
     }

     @Override
     protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {
         int screenWidth = MeasureSpec.getSize(widthMeasureSpec);
         int screenHeight = MeasureSpec.getSize(heightMeasureSpec);

         // Take the width of this view as the width of the screen and compute necessary thresholds.
         // Only do this computation 1x.
         if (mAllowedHorizontalScrollLength == Integer.MIN_VALUE) {
             mMinFragmentWidth = (int) (FRAGMENT_WIDTH_SCREEN_WIDTH_FRACTION * screenWidth);
             mAllowedHorizontalScrollLength = (MAX_FRAGMENT_VIEW_COUNT * mMinFragmentWidth) -
                     screenWidth;
             mLowerThreshold = (screenWidth - mMinFragmentWidth) / MAX_FRAGMENT_VIEW_COUNT;
             mUpperThreshold = mAllowedHorizontalScrollLength - mLowerThreshold;
         }

         if (getChildCount() > 0) {
             View child = getChildAt(0);
             // If we enable swipe, then the {@link LinearLayout} child width must be the sum of the
             // width of all its children fragments.
             // Or the current page may already be set to something other than the first.  If so,
             // it also means there are multiple child fragments.
             if (mEnableSwipe || mCurrentPage != 0) {
                 child.measure(MeasureSpec.makeMeasureSpec(
                         mMinFragmentWidth * MAX_FRAGMENT_VIEW_COUNT, MeasureSpec.EXACTLY),
                         MeasureSpec.makeMeasureSpec(screenHeight, MeasureSpec.EXACTLY));
             } else {
                 // Otherwise, the {@link LinearLayout} child width will just be the screen width
                 // because it will only have 1 child fragment.
                 child.measure(MeasureSpec.makeMeasureSpec(screenWidth, MeasureSpec.EXACTLY),
                         MeasureSpec.makeMeasureSpec(screenHeight, MeasureSpec.EXACTLY));
             }
         }

         setMeasuredDimension(
                 resolveSize(screenWidth, widthMeasureSpec),
                 resolveSize(screenHeight, heightMeasureSpec));
     }

     /**
      * Set the current page. This dims out the non-selected page but doesn't do any scrolling of
      * the carousel.
      */
     public void setCurrentPage(int pageIndex) {
         mCurrentPage = pageIndex;

         updateTouchInterceptors();
     }

     /**
      * Set the view containers for the detail and updates fragment.
      */
     public void setFragmentViews(FrameLayoutWithOverlay about, FrameLayoutWithOverlay updates) {
         mAboutFragment = about;
         mUpdatesFragment = updates;

         mAboutFragment.setOverlayOnClickListener(mAboutFragTouchInterceptListener);
         mUpdatesFragment.setOverlayOnClickListener(mUpdatesFragTouchInterceptListener);
     }

     /**
      * Enable swiping if the detail and update fragments should be showing. Otherwise disable
      * swiping if only the detail fragment should be showing.
      */
     public void enableSwipe(boolean enable) {
         if (mEnableSwipe != enable) {
             mEnableSwipe = enable;
             if (mUpdatesFragment != null) {
                 mUpdatesFragment.setVisibility(enable ? View.VISIBLE : View.GONE);
                 snapToEdge();
                 updateTouchInterceptors();
             }
         }
     }

     /**
      * Reset the fragment carousel to show the about page.
      */
     public void reset() {
         if (mCurrentPage != ABOUT_PAGE) {
             mCurrentPage = ABOUT_PAGE;
             snapToEdgeSmooth();
         }
     }

     public int getCurrentPage() {
         return mCurrentPage;
     }

     private final OnClickListener mAboutFragTouchInterceptListener = new OnClickListener() {
         @Override
         public void onClick(View v) {
             mCurrentPage = ABOUT_PAGE;
             snapToEdgeSmooth();
         }
     };

     private final OnClickListener mUpdatesFragTouchInterceptListener = new OnClickListener() {
         @Override
         public void onClick(View v) {
             mCurrentPage = UPDATES_PAGE;
             snapToEdgeSmooth();
         }
     };

     private void updateTouchInterceptors() {
         // Disable the touch-interceptor on the selected page, and enable it on the other.
         if (mAboutFragment != null) {
             mAboutFragment.setOverlayClickable(mCurrentPage != ABOUT_PAGE);
         }
         if (mUpdatesFragment != null) {
             mUpdatesFragment.setOverlayClickable(mCurrentPage != UPDATES_PAGE);
         }
     }

     @Override
     protected void onScrollChanged(int l, int t, int oldl, int oldt) {
         super.onScrollChanged(l, t, oldl, oldt);
         if (!mEnableSwipe) {
             return;
         }
         mLastScrollPosition = l;
     }

     /**
      * Used to set initial scroll offset.  Not smooth.
      */
     private void snapToEdge() {
         setScrollX(calculateHorizontalOffset());
         updateTouchInterceptors();
     }

     /**
      * Smooth version of snapToEdge().
      */
     private void snapToEdgeSmooth() {
         smoothScrollTo(calculateHorizontalOffset(), 0);
         updateTouchInterceptors();
     }

     private int calculateHorizontalOffset() {
         return mCurrentPage == ABOUT_PAGE ? 0 : mAllowedHorizontalScrollLength;
     }

     /**
      * Returns the desired page we should scroll to based on the current X scroll position and the
      * current page.
      */
     private int getDesiredPage() {
         switch (mCurrentPage) {
             case ABOUT_PAGE:
                 // If the user is on the "about" page, and the scroll position exceeds the lower
                 // threshold, then we should switch to the "updates" page.
                 return (mLastScrollPosition > mLowerThreshold) ? UPDATES_PAGE : ABOUT_PAGE;
             case UPDATES_PAGE:
                 // If the user is on the "updates" page, and the scroll position goes below the
                 // upper threshold, then we should switch to the "about" page.
                 return (mLastScrollPosition < mUpperThreshold) ? ABOUT_PAGE : UPDATES_PAGE;
         }
         throw new IllegalStateException("Invalid current page " + mCurrentPage);
     }

     @Override
     public boolean onTouch(View v, MotionEvent event) {
         if (!mEnableSwipe) {
             return false;
         }
         if (event.getAction() == MotionEvent.ACTION_UP) {
             mCurrentPage = getDesiredPage();
             snapToEdgeSmooth();
             return true;
         }
         return false;
     }

     /**
      * Starts an "appear" animation by moving in the "Updates" from the right.
      */
     public void animateAppear() {
         final int x = Math.round((1.0f - FRAGMENT_WIDTH_SCREEN_WIDTH_FRACTION) * getWidth());
         mUpdatesFragment.setTranslationX(x);
         final ViewPropertyAnimator animator = mUpdatesFragment.animate();
         animator.translationX(0.0f);
     }
 }
	/*
	* 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.android.contacts.detail;

	import android.content.Context;
	import android.util.AttributeSet;
	import android.view.LayoutInflater;
	import android.view.MotionEvent;
	import android.view.View;
	import android.view.View.OnTouchListener;
	import android.view.ViewPropertyAnimator;
	import android.widget.HorizontalScrollView;

	import com.android.contacts.R;
	import com.android.contacts.widget.FrameLayoutWithOverlay;

	/**
	* This is a horizontally scrolling carousel with 2 fragments: one to see info about the contact and
	* one to see updates from the contact. Depending on the scroll position and user selection of which
	* fragment to currently view, the touch interceptors over each fragment are configured accordingly.
	*/
	public class ContactDetailFragmentCarousel extends HorizontalScrollView implements OnTouchListener {

	private static final String TAG = ContactDetailFragmentCarousel.class.getSimpleName();

	/**
	* Number of pixels that this view can be scrolled horizontally.
	*/
	private int mAllowedHorizontalScrollLength = Integer.MIN_VALUE;

	/**
	* Minimum X scroll position that must be surpassed (if the user is on the "about" page of the
	* contact card), in order for this view to automatically snap to the "updates" page.
	*/
	private int mLowerThreshold = Integer.MIN_VALUE;

	/**
	* Maximum X scroll position (if the user is on the "updates" page of the contact card), below
	* which this view will automatically snap to the "about" page.
	*/
	private int mUpperThreshold = Integer.MIN_VALUE;

	/**
	* Minimum width of a fragment (if there is more than 1 fragment in the carousel, then this is
	* the width of one of the fragments).
	*/
	private int mMinFragmentWidth = Integer.MIN_VALUE;

	/**
	* Fragment width (if there are 1+ fragments in the carousel) as defined as a fraction of the
	* screen width.
	*/
	private static final float FRAGMENT_WIDTH_SCREEN_WIDTH_FRACTION = 0.85f;

	private static final int ABOUT_PAGE = 0;
	private static final int UPDATES_PAGE = 1;

	private static final int MAX_FRAGMENT_VIEW_COUNT = 2;

	private boolean mEnableSwipe;

	private int mCurrentPage = ABOUT_PAGE;
	private int mLastScrollPosition;

	private FrameLayoutWithOverlay mAboutFragment;
	private FrameLayoutWithOverlay mUpdatesFragment;

	public ContactDetailFragmentCarousel(Context context) {
	this(context, null);
	}

	public ContactDetailFragmentCarousel(Context context, AttributeSet attrs) {
	this(context, attrs, 0);
	}

	public ContactDetailFragmentCarousel(Context context, AttributeSet attrs, int defStyle) {
	super(context, attrs, defStyle);

	final LayoutInflater inflater =
	(LayoutInflater) mContext.getSystemService(Context.LAYOUT_INFLATER_SERVICE);
	inflater.inflate(R.layout.contact_detail_fragment_carousel, this);

	setOnTouchListener(this);
	}

	@Override
	protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {
	int screenWidth = MeasureSpec.getSize(widthMeasureSpec);
	int screenHeight = MeasureSpec.getSize(heightMeasureSpec);

	// Take the width of this view as the width of the screen and compute necessary thresholds.
	// Only do this computation 1x.
	if (mAllowedHorizontalScrollLength == Integer.MIN_VALUE) {
	mMinFragmentWidth = (int) (FRAGMENT_WIDTH_SCREEN_WIDTH_FRACTION * screenWidth);
	mAllowedHorizontalScrollLength = (MAX_FRAGMENT_VIEW_COUNT * mMinFragmentWidth) -
	screenWidth;
	mLowerThreshold = (screenWidth - mMinFragmentWidth) / MAX_FRAGMENT_VIEW_COUNT;
	mUpperThreshold = mAllowedHorizontalScrollLength - mLowerThreshold;
	}

	if (getChildCount() > 0) {
	View child = getChildAt(0);
	// If we enable swipe, then the {@link LinearLayout} child width must be the sum of the
	// width of all its children fragments.
	// Or the current page may already be set to something other than the first. If so,
	// it also means there are multiple child fragments.
	if (mEnableSwipe \|\| mCurrentPage != 0) {
	child.measure(MeasureSpec.makeMeasureSpec(
	mMinFragmentWidth * MAX_FRAGMENT_VIEW_COUNT, MeasureSpec.EXACTLY),
	MeasureSpec.makeMeasureSpec(screenHeight, MeasureSpec.EXACTLY));
	} else {
	// Otherwise, the {@link LinearLayout} child width will just be the screen width
	// because it will only have 1 child fragment.
	child.measure(MeasureSpec.makeMeasureSpec(screenWidth, MeasureSpec.EXACTLY),
	MeasureSpec.makeMeasureSpec(screenHeight, MeasureSpec.EXACTLY));
	}
	}

	setMeasuredDimension(
	resolveSize(screenWidth, widthMeasureSpec),
	resolveSize(screenHeight, heightMeasureSpec));
	}

	/**
	* Set the current page. This dims out the non-selected page but doesn't do any scrolling of
	* the carousel.
	*/
	public void setCurrentPage(int pageIndex) {
	mCurrentPage = pageIndex;

	updateTouchInterceptors();
	}

	/**
	* Set the view containers for the detail and updates fragment.
	*/
	public void setFragmentViews(FrameLayoutWithOverlay about, FrameLayoutWithOverlay updates) {
	mAboutFragment = about;
	mUpdatesFragment = updates;

	mAboutFragment.setOverlayOnClickListener(mAboutFragTouchInterceptListener);
	mUpdatesFragment.setOverlayOnClickListener(mUpdatesFragTouchInterceptListener);
	}

	/**
	* Enable swiping if the detail and update fragments should be showing. Otherwise disable
	* swiping if only the detail fragment should be showing.
	*/
	public void enableSwipe(boolean enable) {
	if (mEnableSwipe != enable) {
	mEnableSwipe = enable;
	if (mUpdatesFragment != null) {
	mUpdatesFragment.setVisibility(enable ? View.VISIBLE : View.GONE);
	snapToEdge();
	updateTouchInterceptors();
	}
	}
	}

	/**
	* Reset the fragment carousel to show the about page.
	*/
	public void reset() {
	if (mCurrentPage != ABOUT_PAGE) {
	mCurrentPage = ABOUT_PAGE;
	snapToEdgeSmooth();
	}
	}

	public int getCurrentPage() {
	return mCurrentPage;
	}

	private final OnClickListener mAboutFragTouchInterceptListener = new OnClickListener() {
	@Override
	public void onClick(View v) {
	mCurrentPage = ABOUT_PAGE;
	snapToEdgeSmooth();
	}
	};

	private final OnClickListener mUpdatesFragTouchInterceptListener = new OnClickListener() {
	@Override
	public void onClick(View v) {
	mCurrentPage = UPDATES_PAGE;
	snapToEdgeSmooth();
	}
	};

	private void updateTouchInterceptors() {
	// Disable the touch-interceptor on the selected page, and enable it on the other.
	if (mAboutFragment != null) {
	mAboutFragment.setOverlayClickable(mCurrentPage != ABOUT_PAGE);
	}
	if (mUpdatesFragment != null) {
	mUpdatesFragment.setOverlayClickable(mCurrentPage != UPDATES_PAGE);
	}
	}

	@Override
	protected void onScrollChanged(int l, int t, int oldl, int oldt) {
	super.onScrollChanged(l, t, oldl, oldt);
	if (!mEnableSwipe) {
	return;
	}
	mLastScrollPosition = l;
	}

	/**
	* Used to set initial scroll offset. Not smooth.
	*/
	private void snapToEdge() {
	setScrollX(calculateHorizontalOffset());
	updateTouchInterceptors();
	}

	/**
	* Smooth version of snapToEdge().
	*/
	private void snapToEdgeSmooth() {
	smoothScrollTo(calculateHorizontalOffset(), 0);
	updateTouchInterceptors();
	}

	private int calculateHorizontalOffset() {
	return mCurrentPage == ABOUT_PAGE ? 0 : mAllowedHorizontalScrollLength;
	}

	/**
	* Returns the desired page we should scroll to based on the current X scroll position and the
	* current page.
	*/
	private int getDesiredPage() {
	switch (mCurrentPage) {
	case ABOUT_PAGE:
	// If the user is on the "about" page, and the scroll position exceeds the lower
	// threshold, then we should switch to the "updates" page.
	return (mLastScrollPosition > mLowerThreshold) ? UPDATES_PAGE : ABOUT_PAGE;
	case UPDATES_PAGE:
	// If the user is on the "updates" page, and the scroll position goes below the
	// upper threshold, then we should switch to the "about" page.
	return (mLastScrollPosition < mUpperThreshold) ? ABOUT_PAGE : UPDATES_PAGE;
	}
	throw new IllegalStateException("Invalid current page " + mCurrentPage);
	}

	@Override
	public boolean onTouch(View v, MotionEvent event) {
	if (!mEnableSwipe) {
	return false;
	}
	if (event.getAction() == MotionEvent.ACTION_UP) {
	mCurrentPage = getDesiredPage();
	snapToEdgeSmooth();
	return true;
	}
	return false;
	}

	/**
	* Starts an "appear" animation by moving in the "Updates" from the right.
	*/
	public void animateAppear() {
	final int x = Math.round((1.0f - FRAGMENT_WIDTH_SCREEN_WIDTH_FRACTION) * getWidth());
	mUpdatesFragment.setTranslationX(x);
	final ViewPropertyAnimator animator = mUpdatesFragment.animate();
	animator.translationX(0.0f);
	}
	}