src/com/android/calculator2/CalculatorPadViewPager.java - platform/packages/apps/ExactCalculator - Git at Google

 /*
  * 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 com.android.calculator2;

 import android.content.Context;
 import android.graphics.Color;
 import android.support.v4.view.PagerAdapter;
 import android.support.v4.view.ViewPager;
 import android.util.AttributeSet;
 import android.util.Log;
 import android.view.GestureDetector;
 import android.view.MotionEvent;
 import android.view.View;
 import android.view.ViewGroup;

 public class CalculatorPadViewPager extends ViewPager {

     private final PagerAdapter mStaticPagerAdapter = new PagerAdapter() {
         @Override
         public int getCount() {
             return getChildCount();
         }

         @Override
         public View instantiateItem(ViewGroup container, final int position) {
             final View child = getChildAt(position);

             // Set a OnClickListener to scroll to item's position when it isn't the current item.
             child.setOnClickListener(new OnClickListener() {
                 @Override
                 public void onClick(View v) {
                     setCurrentItem(position, true /* smoothScroll */);
                 }
             });
             // Set an OnTouchListener to always return true for onTouch events so that a touch
             // sequence cannot pass through the item to the item below.
             child.setOnTouchListener(new OnTouchListener() {
                 @Override
                 public boolean onTouch(View v, MotionEvent event) {
                     v.onTouchEvent(event);
                     return true;
                 }
             });

             // Set an OnHoverListener to always return true for onHover events so that focus cannot
             // pass through the item to the item below.
             child.setOnHoverListener(new OnHoverListener() {
                 @Override
                 public boolean onHover(View v, MotionEvent event) {
                     v.onHoverEvent(event);
                     return true;
                 }
             });
             // Make the item focusable so it can be selected via a11y.
             child.setFocusable(true);
             // Set the content description of the item which will be used by a11y to identify it.
             child.setContentDescription(getPageTitle(position));

             return child;
         }

         @Override
         public void destroyItem(ViewGroup container, int position, Object object) {
             removeViewAt(position);
         }

         @Override
         public boolean isViewFromObject(View view, Object object) {
             return view == object;
         }

         @Override
         public float getPageWidth(int position) {
             return position == 1 ? 7.0f / 9.0f : 1.0f;
         }

         @Override
         public CharSequence getPageTitle(int position) {
             final String[] pageDescriptions = getContext().getResources()
                     .getStringArray(R.array.desc_pad_pages);
             return pageDescriptions[position];
         }
     };

     private final OnPageChangeListener mOnPageChangeListener = new SimpleOnPageChangeListener() {
         @Override
         public void onPageSelected(int position) {
             for (int i = getChildCount() - 1; i >= 0; --i) {
                 final View child = getChildAt(i);
                 // Only the "peeking" or covered page should be clickable.
                 child.setClickable(i != position);

                 // Prevent clicks and accessibility focus from going through to descendants of
                 // other pages which are covered by the current page.
                 if (child instanceof ViewGroup) {
                     final ViewGroup childViewGroup = (ViewGroup) child;
                     for (int j = childViewGroup.getChildCount() - 1; j >= 0; --j) {
                         childViewGroup.getChildAt(j)
                                 .setImportantForAccessibility(i == position
                                         ? IMPORTANT_FOR_ACCESSIBILITY_AUTO
                                         : IMPORTANT_FOR_ACCESSIBILITY_NO_HIDE_DESCENDANTS);
                     }
                 }
             }
         }
     };

     private final PageTransformer mPageTransformer = new PageTransformer() {
         @Override
         public void transformPage(View view, float position) {
             if (position < 0.0f) {
                 // Pin the left page to the left side.
                 view.setTranslationX(getWidth() * -position);
                 view.setAlpha(Math.max(1.0f + position, 0.0f));
             } else {
                 // Use the default slide transition when moving to the next page.
                 view.setTranslationX(0.0f);
                 view.setAlpha(1.0f);
             }
         }
     };

     private final GestureDetector.SimpleOnGestureListener mGestureWatcher =
             new GestureDetector.SimpleOnGestureListener() {
         @Override
         public boolean onDown(MotionEvent e) {
             // Return true so calls to onSingleTapUp are not blocked.
             return true;
         }

         @Override
         public boolean onSingleTapUp(MotionEvent ev) {
             if (mClickedItemIndex != -1) {
                 getChildAt(mClickedItemIndex).performClick();
                 mClickedItemIndex = -1;
                 return true;
             }
             return super.onSingleTapUp(ev);
         }
     };

     private final GestureDetector mGestureDetector;

     private int mClickedItemIndex = -1;

     public CalculatorPadViewPager(Context context) {
         this(context, null /* attrs */);
     }

     public CalculatorPadViewPager(Context context, AttributeSet attrs) {
         super(context, attrs);

         mGestureDetector = new GestureDetector(context, mGestureWatcher);
         mGestureDetector.setIsLongpressEnabled(false);

         setAdapter(mStaticPagerAdapter);
         setBackgroundColor(Color.BLACK);
         setPageMargin(-getResources().getDimensionPixelSize(R.dimen.pad_page_margin));
         setPageTransformer(false, mPageTransformer);
         addOnPageChangeListener(mOnPageChangeListener);
     }

     @Override
     protected void onFinishInflate() {
         super.onFinishInflate();

         // Invalidate the adapter's data set since children may have been added during inflation.
         getAdapter().notifyDataSetChanged();

         // Let page change listener know about our initial position.
         mOnPageChangeListener.onPageSelected(getCurrentItem());
     }

     @Override
     public boolean onInterceptTouchEvent(MotionEvent ev) {
         try {
             // Always intercept touch events when a11y focused since otherwise they will be
             // incorrectly offset by a11y before being dispatched to children.
             if (isAccessibilityFocused() || super.onInterceptTouchEvent(ev)) {
                 return true;
             }

             // Only allow the current item to receive touch events.
             final int action = ev.getActionMasked();
             if (action == MotionEvent.ACTION_DOWN || action == MotionEvent.ACTION_POINTER_DOWN) {
                 // If a child is a11y focused then we must always intercept the touch event
                 // since it will be incorrectly offset by a11y.
                 final int childCount = getChildCount();
                 for (int childIndex = childCount - 1; childIndex >= 0; --childIndex) {
                     if (getChildAt(childIndex).isAccessibilityFocused()) {
                         mClickedItemIndex = childIndex;
                         return true;
                     }
                 }

                 if (action == MotionEvent.ACTION_DOWN) {
                     mClickedItemIndex = -1;
                 }

                 // Otherwise if touch is on a non-current item then intercept.
                 final int actionIndex = ev.getActionIndex();
                 final float x = ev.getX(actionIndex) + getScrollX();
                 final float y = ev.getY(actionIndex) + getScrollY();
                 for (int i = childCount - 1; i >= 0; --i) {
                     final int childIndex = getChildDrawingOrder(childCount, i);
                     final View child = getChildAt(childIndex);
                     if (child.getVisibility() == VISIBLE
                             && x >= child.getLeft() && x < child.getRight()
                             && y >= child.getTop() && y < child.getBottom()) {
                         if (action == MotionEvent.ACTION_DOWN) {
                             mClickedItemIndex = childIndex;
                         }
                         return childIndex != getCurrentItem();
                     }
                 }
             }

             return false;
         } catch (IllegalArgumentException e) {
             Log.e("Calculator", "Error intercepting touch event", e);
             return false;
         }
     }

     @Override
     public boolean onTouchEvent(MotionEvent ev) {
         try {
             // Allow both the gesture detector and super to handle the touch event so they both see
             // the full sequence of events. This should be safe since the gesture detector only
             // handle clicks and super only handles swipes.
             mGestureDetector.onTouchEvent(ev);
             return super.onTouchEvent(ev);
         } catch (IllegalArgumentException e) {
             Log.e("Calculator", "Error processing touch event", e);
             return false;
         }
     }
 }
	/*
	* 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 com.android.calculator2;

	import android.content.Context;
	import android.graphics.Color;
	import android.support.v4.view.PagerAdapter;
	import android.support.v4.view.ViewPager;
	import android.util.AttributeSet;
	import android.util.Log;
	import android.view.GestureDetector;
	import android.view.MotionEvent;
	import android.view.View;
	import android.view.ViewGroup;

	public class CalculatorPadViewPager extends ViewPager {

	private final PagerAdapter mStaticPagerAdapter = new PagerAdapter() {
	@Override
	public int getCount() {
	return getChildCount();
	}

	@Override
	public View instantiateItem(ViewGroup container, final int position) {
	final View child = getChildAt(position);

	// Set a OnClickListener to scroll to item's position when it isn't the current item.
	child.setOnClickListener(new OnClickListener() {
	@Override
	public void onClick(View v) {
	setCurrentItem(position, true /* smoothScroll */);
	}
	});
	// Set an OnTouchListener to always return true for onTouch events so that a touch
	// sequence cannot pass through the item to the item below.
	child.setOnTouchListener(new OnTouchListener() {
	@Override
	public boolean onTouch(View v, MotionEvent event) {
	v.onTouchEvent(event);
	return true;
	}
	});

	// Set an OnHoverListener to always return true for onHover events so that focus cannot
	// pass through the item to the item below.
	child.setOnHoverListener(new OnHoverListener() {
	@Override
	public boolean onHover(View v, MotionEvent event) {
	v.onHoverEvent(event);
	return true;
	}
	});
	// Make the item focusable so it can be selected via a11y.
	child.setFocusable(true);
	// Set the content description of the item which will be used by a11y to identify it.
	child.setContentDescription(getPageTitle(position));

	return child;
	}

	@Override
	public void destroyItem(ViewGroup container, int position, Object object) {
	removeViewAt(position);
	}

	@Override
	public boolean isViewFromObject(View view, Object object) {
	return view == object;
	}

	@Override
	public float getPageWidth(int position) {
	return position == 1 ? 7.0f / 9.0f : 1.0f;
	}

	@Override
	public CharSequence getPageTitle(int position) {
	final String[] pageDescriptions = getContext().getResources()
	.getStringArray(R.array.desc_pad_pages);
	return pageDescriptions[position];
	}
	};

	private final OnPageChangeListener mOnPageChangeListener = new SimpleOnPageChangeListener() {
	@Override
	public void onPageSelected(int position) {
	for (int i = getChildCount() - 1; i >= 0; --i) {
	final View child = getChildAt(i);
	// Only the "peeking" or covered page should be clickable.
	child.setClickable(i != position);

	// Prevent clicks and accessibility focus from going through to descendants of
	// other pages which are covered by the current page.
	if (child instanceof ViewGroup) {
	final ViewGroup childViewGroup = (ViewGroup) child;
	for (int j = childViewGroup.getChildCount() - 1; j >= 0; --j) {
	childViewGroup.getChildAt(j)
	.setImportantForAccessibility(i == position
	? IMPORTANT_FOR_ACCESSIBILITY_AUTO
	: IMPORTANT_FOR_ACCESSIBILITY_NO_HIDE_DESCENDANTS);
	}
	}
	}
	}
	};

	private final PageTransformer mPageTransformer = new PageTransformer() {
	@Override
	public void transformPage(View view, float position) {
	if (position < 0.0f) {
	// Pin the left page to the left side.
	view.setTranslationX(getWidth() * -position);
	view.setAlpha(Math.max(1.0f + position, 0.0f));
	} else {
	// Use the default slide transition when moving to the next page.
	view.setTranslationX(0.0f);
	view.setAlpha(1.0f);
	}
	}
	};

	private final GestureDetector.SimpleOnGestureListener mGestureWatcher =
	new GestureDetector.SimpleOnGestureListener() {
	@Override
	public boolean onDown(MotionEvent e) {
	// Return true so calls to onSingleTapUp are not blocked.
	return true;
	}

	@Override
	public boolean onSingleTapUp(MotionEvent ev) {
	if (mClickedItemIndex != -1) {
	getChildAt(mClickedItemIndex).performClick();
	mClickedItemIndex = -1;
	return true;
	}
	return super.onSingleTapUp(ev);
	}
	};

	private final GestureDetector mGestureDetector;

	private int mClickedItemIndex = -1;

	public CalculatorPadViewPager(Context context) {
	this(context, null /* attrs */);
	}

	public CalculatorPadViewPager(Context context, AttributeSet attrs) {
	super(context, attrs);

	mGestureDetector = new GestureDetector(context, mGestureWatcher);
	mGestureDetector.setIsLongpressEnabled(false);

	setAdapter(mStaticPagerAdapter);
	setBackgroundColor(Color.BLACK);
	setPageMargin(-getResources().getDimensionPixelSize(R.dimen.pad_page_margin));
	setPageTransformer(false, mPageTransformer);
	addOnPageChangeListener(mOnPageChangeListener);
	}

	@Override
	protected void onFinishInflate() {
	super.onFinishInflate();

	// Invalidate the adapter's data set since children may have been added during inflation.
	getAdapter().notifyDataSetChanged();

	// Let page change listener know about our initial position.
	mOnPageChangeListener.onPageSelected(getCurrentItem());
	}

	@Override
	public boolean onInterceptTouchEvent(MotionEvent ev) {
	try {
	// Always intercept touch events when a11y focused since otherwise they will be
	// incorrectly offset by a11y before being dispatched to children.
	if (isAccessibilityFocused() \|\| super.onInterceptTouchEvent(ev)) {
	return true;
	}

	// Only allow the current item to receive touch events.
	final int action = ev.getActionMasked();
	if (action == MotionEvent.ACTION_DOWN \|\| action == MotionEvent.ACTION_POINTER_DOWN) {
	// If a child is a11y focused then we must always intercept the touch event
	// since it will be incorrectly offset by a11y.
	final int childCount = getChildCount();
	for (int childIndex = childCount - 1; childIndex >= 0; --childIndex) {
	if (getChildAt(childIndex).isAccessibilityFocused()) {
	mClickedItemIndex = childIndex;
	return true;
	}
	}

	if (action == MotionEvent.ACTION_DOWN) {
	mClickedItemIndex = -1;
	}

	// Otherwise if touch is on a non-current item then intercept.
	final int actionIndex = ev.getActionIndex();
	final float x = ev.getX(actionIndex) + getScrollX();
	final float y = ev.getY(actionIndex) + getScrollY();
	for (int i = childCount - 1; i >= 0; --i) {
	final int childIndex = getChildDrawingOrder(childCount, i);
	final View child = getChildAt(childIndex);
	if (child.getVisibility() == VISIBLE
	&& x >= child.getLeft() && x < child.getRight()
	&& y >= child.getTop() && y < child.getBottom()) {
	if (action == MotionEvent.ACTION_DOWN) {
	mClickedItemIndex = childIndex;
	}
	return childIndex != getCurrentItem();
	}
	}
	}

	return false;
	} catch (IllegalArgumentException e) {
	Log.e("Calculator", "Error intercepting touch event", e);
	return false;
	}
	}

	@Override
	public boolean onTouchEvent(MotionEvent ev) {
	try {
	// Allow both the gesture detector and super to handle the touch event so they both see
	// the full sequence of events. This should be safe since the gesture detector only
	// handle clicks and super only handles swipes.
	mGestureDetector.onTouchEvent(ev);
	return super.onTouchEvent(ev);
	} catch (IllegalArgumentException e) {
	Log.e("Calculator", "Error processing touch event", e);
	return false;
	}
	}
	}