samples/Home/src/com/example/android/home/ApplicationsStackLayout.java - platform/development - Git at Google

 /*
  * Copyright (C) 2007 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.example.android.home;

 import android.content.Context;
 import android.content.Intent;
 import android.content.res.TypedArray;
 import android.graphics.Canvas;
 import android.graphics.Rect;
 import android.graphics.drawable.Drawable;
 import android.util.AttributeSet;
 import android.view.View;
 import android.view.ViewGroup;
 import android.view.LayoutInflater;
 import android.widget.TextView;

 import java.util.List;

 /**
  * The ApplicationsStackLayout is a specialized layout used for the purpose of the home screen
  * only. This layout stacks various icons in three distinct areas: the recents, the favorites
  * (or faves) and the button.
  *
  * This layout supports two different orientations: vertical and horizontal. When horizontal,
  * the areas are laid out this way:
  *
  * [RECENTS][FAVES][BUTTON]
  *
  * When vertical, the layout is the following:
  *
  * [RECENTS]
  * [FAVES]
  * [BUTTON]
  *
  * The layout operates from the "bottom up" (or from right to left.) This means that the button
  * area will first be laid out, then the faves area, then the recents. When there are too many
  * favorites, the recents area is not displayed.
  *
  * The following attributes can be set in XML:
  *
  * orientation: horizontal or vertical
  * marginLeft: the left margin of each element in the stack
  * marginTop: the top margin of each element in the stack
  * marginRight: the right margin of each element in the stack
  * marginBottom: the bottom margin of each element in the stack
  */
 public class ApplicationsStackLayout extends ViewGroup implements View.OnClickListener {
     public static final int HORIZONTAL = 0;
     public static final int VERTICAL = 1;

     private View mButton;
     private LayoutInflater mInflater;

     private int mFavoritesEnd;
     private int mFavoritesStart;

     private List<ApplicationInfo> mFavorites;
     private List<ApplicationInfo> mRecents;

     private int mOrientation = VERTICAL;

     private int mMarginLeft;
     private int mMarginTop;
     private int mMarginRight;
     private int mMarginBottom;

     private Rect mDrawRect = new Rect();

     private Drawable mBackground;
     private int mIconSize;

     public ApplicationsStackLayout(Context context) {
         super(context);
         initLayout();
     }

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

         TypedArray a =
                 context.obtainStyledAttributes(attrs, R.styleable.ApplicationsStackLayout);

         mOrientation = a.getInt(R.styleable.ApplicationsStackLayout_stackOrientation, VERTICAL);

         mMarginLeft = a.getDimensionPixelSize(R.styleable.ApplicationsStackLayout_marginLeft, 0);
         mMarginTop = a.getDimensionPixelSize(R.styleable.ApplicationsStackLayout_marginTop, 0);
         mMarginRight = a.getDimensionPixelSize(R.styleable.ApplicationsStackLayout_marginRight, 0);
         mMarginBottom = a.getDimensionPixelSize(R.styleable.ApplicationsStackLayout_marginBottom, 0);

         a.recycle();

         mIconSize = 42; //(int) getResources().getDimension(android.R.dimen.app_icon_size);

         initLayout();
     }

     private void initLayout() {
         mInflater = LayoutInflater.from(getContext());
         mButton = mInflater.inflate(R.layout.all_applications_button, this, false);
         addView(mButton);

         mBackground = getBackground();
         setBackgroundDrawable(null);
         setWillNotDraw(false);
     }

     /**
      * Return the current orientation, either VERTICAL (default) or HORIZONTAL.
      *
      * @return the stack orientation
      */
     public int getOrientation() {
         return mOrientation;
     }

     @Override
     protected void onDraw(Canvas canvas) {
         final Drawable background = mBackground;

         final int right = getWidth();
         final int bottom = getHeight();

         // Draw behind recents
         if (mOrientation == VERTICAL) {
             mDrawRect.set(0, 0, right, mFavoritesStart);
         } else {
             mDrawRect.set(0, 0, mFavoritesStart, bottom);
         }
         background.setBounds(mDrawRect);
         background.draw(canvas);

         // Draw behind favorites
         if (mFavoritesStart > -1) {
             if (mOrientation == VERTICAL) {
                 mDrawRect.set(0, mFavoritesStart, right, mFavoritesEnd);
             } else {
                 mDrawRect.set(mFavoritesStart, 0, mFavoritesEnd, bottom);
             }
             background.setBounds(mDrawRect);
             background.draw(canvas);
         }

         super.onDraw(canvas);
     }

     @Override
     protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {
         super.onMeasure(widthMeasureSpec, heightMeasureSpec);

         final int widthMode = MeasureSpec.getMode(widthMeasureSpec);
         final int widthSize = MeasureSpec.getSize(widthMeasureSpec);

         final int heightMode = MeasureSpec.getMode(heightMeasureSpec);
         final int heightSize = MeasureSpec.getSize(heightMeasureSpec);

         if (widthMode != MeasureSpec.EXACTLY || heightMode != MeasureSpec.EXACTLY) {
             throw new IllegalStateException("ApplicationsStackLayout can only be used with "
                     + "measure spec mode=EXACTLY");
         }

         setMeasuredDimension(widthSize, heightSize);
     }

     @Override
     protected void onLayout(boolean changed, int l, int t, int r, int b) {
         removeAllApplications();

         LayoutParams layoutParams = mButton.getLayoutParams();
         final int widthSpec = MeasureSpec.makeMeasureSpec(layoutParams.width, MeasureSpec.EXACTLY);
         final int heightSpec = MeasureSpec.makeMeasureSpec(layoutParams.height, MeasureSpec.EXACTLY);
         mButton.measure(widthSpec, heightSpec);

         if (mOrientation == VERTICAL) {
             layoutVertical();
         } else {
             layoutHorizontal();
         }
     }

     private void layoutVertical() {
         int childLeft = 0;
         int childTop = getHeight();

         int childWidth = mButton.getMeasuredWidth();
         int childHeight = mButton.getMeasuredHeight();

         childTop -= childHeight + mMarginBottom;
         mButton.layout(childLeft, childTop, childLeft + childWidth, childTop + childHeight);
         childTop -= mMarginTop;
         mFavoritesEnd = childTop - mMarginBottom;

         int oldChildTop = childTop;
         childTop = stackApplications(mFavorites, childLeft, childTop);
         if (childTop != oldChildTop) {
             mFavoritesStart = childTop + mMarginTop;
         } else {
             mFavoritesStart = -1;
         }

         stackApplications(mRecents, childLeft, childTop);
     }

     private void layoutHorizontal() {
         int childLeft = getWidth();
         int childTop = 0;

         int childWidth = mButton.getMeasuredWidth();
         int childHeight = mButton.getMeasuredHeight();

         childLeft -= childWidth;
         mButton.layout(childLeft, childTop, childLeft + childWidth, childTop + childHeight);
         childLeft -= mMarginLeft;
         mFavoritesEnd = childLeft - mMarginRight;

         int oldChildLeft = childLeft;
         childLeft = stackApplications(mFavorites, childLeft, childTop);
         if (childLeft != oldChildLeft) {
             mFavoritesStart = childLeft + mMarginLeft;
         } else {
             mFavoritesStart = -1;
         }

         stackApplications(mRecents, childLeft, childTop);
     }

     private int stackApplications(List<ApplicationInfo> applications, int childLeft, int childTop) {
         LayoutParams layoutParams;
         int widthSpec;
         int heightSpec;
         int childWidth;
         int childHeight;

         final boolean isVertical = mOrientation == VERTICAL;

         final int count = applications.size();
         for (int i = count - 1; i >= 0; i--) {
             final ApplicationInfo info = applications.get(i);
             final View view = createApplicationIcon(mInflater, this, info);

             layoutParams = view.getLayoutParams();
             widthSpec = MeasureSpec.makeMeasureSpec(layoutParams.width, MeasureSpec.EXACTLY);
             heightSpec = MeasureSpec.makeMeasureSpec(layoutParams.height, MeasureSpec.EXACTLY);
             view.measure(widthSpec, heightSpec);

             childWidth = view.getMeasuredWidth();
             childHeight = view.getMeasuredHeight();

             if (isVertical) {
                 childTop -= childHeight + mMarginBottom;

                 if (childTop < 0) {
                     childTop += childHeight + mMarginBottom;
                     break;
                 }
             } else {
                 childLeft -= childWidth + mMarginRight;

                 if (childLeft < 0) {
                     childLeft += childWidth + mMarginRight;
                     break;
                 }
             }

             addViewInLayout(view, -1, layoutParams);

             view.layout(childLeft, childTop, childLeft + childWidth, childTop + childHeight);

             if (isVertical) {
                 childTop -= mMarginTop;
             } else {
                 childLeft -= mMarginLeft;
             }
         }

         return isVertical ? childTop : childLeft;
     }

     private void removeAllApplications() {
         final int count = getChildCount();
         for (int i = count - 1; i >= 0; i--) {
             final View view = getChildAt(i);
             if (view != mButton) {
                 removeViewAt(i);
             }
         }
     }

     private View createApplicationIcon(LayoutInflater inflater,
             ViewGroup group, ApplicationInfo info) {

         TextView textView = (TextView) inflater.inflate(R.layout.favorite, group, false);

         info.icon.setBounds(0, 0, mIconSize, mIconSize);
         textView.setCompoundDrawables(null, info.icon, null, null);
         textView.setText(info.title);

         textView.setTag(info.intent);
         textView.setOnClickListener(this);

         return textView;
     }

     /**
      * Sets the list of favorites.
      *
      * @param applications the applications to put in the favorites area
      */
     public void setFavorites(List<ApplicationInfo> applications) {
         mFavorites = applications;
         requestLayout();
     }

     /**
      * Sets the list of recents.
      *
      * @param applications the applications to put in the recents area
      */
     public void setRecents(List<ApplicationInfo> applications) {
         mRecents = applications;
         requestLayout();
     }

     public void onClick(View v) {
         getContext().startActivity((Intent) v.getTag());
     }
 }
	/*
	* Copyright (C) 2007 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.example.android.home;

	import android.content.Context;
	import android.content.Intent;
	import android.content.res.TypedArray;
	import android.graphics.Canvas;
	import android.graphics.Rect;
	import android.graphics.drawable.Drawable;
	import android.util.AttributeSet;
	import android.view.View;
	import android.view.ViewGroup;
	import android.view.LayoutInflater;
	import android.widget.TextView;

	import java.util.List;

	/**
	* The ApplicationsStackLayout is a specialized layout used for the purpose of the home screen
	* only. This layout stacks various icons in three distinct areas: the recents, the favorites
	* (or faves) and the button.
	*
	* This layout supports two different orientations: vertical and horizontal. When horizontal,
	* the areas are laid out this way:
	*
	* [RECENTS][FAVES][BUTTON]
	*
	* When vertical, the layout is the following:
	*
	* [RECENTS]
	* [FAVES]
	* [BUTTON]
	*
	* The layout operates from the "bottom up" (or from right to left.) This means that the button
	* area will first be laid out, then the faves area, then the recents. When there are too many
	* favorites, the recents area is not displayed.
	*
	* The following attributes can be set in XML:
	*
	* orientation: horizontal or vertical
	* marginLeft: the left margin of each element in the stack
	* marginTop: the top margin of each element in the stack
	* marginRight: the right margin of each element in the stack
	* marginBottom: the bottom margin of each element in the stack
	*/
	public class ApplicationsStackLayout extends ViewGroup implements View.OnClickListener {
	public static final int HORIZONTAL = 0;
	public static final int VERTICAL = 1;

	private View mButton;
	private LayoutInflater mInflater;

	private int mFavoritesEnd;
	private int mFavoritesStart;

	private List<ApplicationInfo> mFavorites;
	private List<ApplicationInfo> mRecents;

	private int mOrientation = VERTICAL;

	private int mMarginLeft;
	private int mMarginTop;
	private int mMarginRight;
	private int mMarginBottom;

	private Rect mDrawRect = new Rect();

	private Drawable mBackground;
	private int mIconSize;

	public ApplicationsStackLayout(Context context) {
	super(context);
	initLayout();
	}

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

	TypedArray a =
	context.obtainStyledAttributes(attrs, R.styleable.ApplicationsStackLayout);

	mOrientation = a.getInt(R.styleable.ApplicationsStackLayout_stackOrientation, VERTICAL);

	mMarginLeft = a.getDimensionPixelSize(R.styleable.ApplicationsStackLayout_marginLeft, 0);
	mMarginTop = a.getDimensionPixelSize(R.styleable.ApplicationsStackLayout_marginTop, 0);
	mMarginRight = a.getDimensionPixelSize(R.styleable.ApplicationsStackLayout_marginRight, 0);
	mMarginBottom = a.getDimensionPixelSize(R.styleable.ApplicationsStackLayout_marginBottom, 0);

	a.recycle();

	mIconSize = 42; //(int) getResources().getDimension(android.R.dimen.app_icon_size);

	initLayout();
	}

	private void initLayout() {
	mInflater = LayoutInflater.from(getContext());
	mButton = mInflater.inflate(R.layout.all_applications_button, this, false);
	addView(mButton);

	mBackground = getBackground();
	setBackgroundDrawable(null);
	setWillNotDraw(false);
	}

	/**
	* Return the current orientation, either VERTICAL (default) or HORIZONTAL.
	*
	* @return the stack orientation
	*/
	public int getOrientation() {
	return mOrientation;
	}

	@Override
	protected void onDraw(Canvas canvas) {
	final Drawable background = mBackground;

	final int right = getWidth();
	final int bottom = getHeight();

	// Draw behind recents
	if (mOrientation == VERTICAL) {
	mDrawRect.set(0, 0, right, mFavoritesStart);
	} else {
	mDrawRect.set(0, 0, mFavoritesStart, bottom);
	}
	background.setBounds(mDrawRect);
	background.draw(canvas);

	// Draw behind favorites
	if (mFavoritesStart > -1) {
	if (mOrientation == VERTICAL) {
	mDrawRect.set(0, mFavoritesStart, right, mFavoritesEnd);
	} else {
	mDrawRect.set(mFavoritesStart, 0, mFavoritesEnd, bottom);
	}
	background.setBounds(mDrawRect);
	background.draw(canvas);
	}

	super.onDraw(canvas);
	}

	@Override
	protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {
	super.onMeasure(widthMeasureSpec, heightMeasureSpec);

	final int widthMode = MeasureSpec.getMode(widthMeasureSpec);
	final int widthSize = MeasureSpec.getSize(widthMeasureSpec);

	final int heightMode = MeasureSpec.getMode(heightMeasureSpec);
	final int heightSize = MeasureSpec.getSize(heightMeasureSpec);

	if (widthMode != MeasureSpec.EXACTLY \|\| heightMode != MeasureSpec.EXACTLY) {
	throw new IllegalStateException("ApplicationsStackLayout can only be used with "
	+ "measure spec mode=EXACTLY");
	}

	setMeasuredDimension(widthSize, heightSize);
	}

	@Override
	protected void onLayout(boolean changed, int l, int t, int r, int b) {
	removeAllApplications();

	LayoutParams layoutParams = mButton.getLayoutParams();
	final int widthSpec = MeasureSpec.makeMeasureSpec(layoutParams.width, MeasureSpec.EXACTLY);
	final int heightSpec = MeasureSpec.makeMeasureSpec(layoutParams.height, MeasureSpec.EXACTLY);
	mButton.measure(widthSpec, heightSpec);

	if (mOrientation == VERTICAL) {
	layoutVertical();
	} else {
	layoutHorizontal();
	}
	}

	private void layoutVertical() {
	int childLeft = 0;
	int childTop = getHeight();

	int childWidth = mButton.getMeasuredWidth();
	int childHeight = mButton.getMeasuredHeight();

	childTop -= childHeight + mMarginBottom;
	mButton.layout(childLeft, childTop, childLeft + childWidth, childTop + childHeight);
	childTop -= mMarginTop;
	mFavoritesEnd = childTop - mMarginBottom;

	int oldChildTop = childTop;
	childTop = stackApplications(mFavorites, childLeft, childTop);
	if (childTop != oldChildTop) {
	mFavoritesStart = childTop + mMarginTop;
	} else {
	mFavoritesStart = -1;
	}

	stackApplications(mRecents, childLeft, childTop);
	}

	private void layoutHorizontal() {
	int childLeft = getWidth();
	int childTop = 0;

	int childWidth = mButton.getMeasuredWidth();
	int childHeight = mButton.getMeasuredHeight();

	childLeft -= childWidth;
	mButton.layout(childLeft, childTop, childLeft + childWidth, childTop + childHeight);
	childLeft -= mMarginLeft;
	mFavoritesEnd = childLeft - mMarginRight;

	int oldChildLeft = childLeft;
	childLeft = stackApplications(mFavorites, childLeft, childTop);
	if (childLeft != oldChildLeft) {
	mFavoritesStart = childLeft + mMarginLeft;
	} else {
	mFavoritesStart = -1;
	}

	stackApplications(mRecents, childLeft, childTop);
	}

	private int stackApplications(List<ApplicationInfo> applications, int childLeft, int childTop) {
	LayoutParams layoutParams;
	int widthSpec;
	int heightSpec;
	int childWidth;
	int childHeight;

	final boolean isVertical = mOrientation == VERTICAL;

	final int count = applications.size();
	for (int i = count - 1; i >= 0; i--) {
	final ApplicationInfo info = applications.get(i);
	final View view = createApplicationIcon(mInflater, this, info);

	layoutParams = view.getLayoutParams();
	widthSpec = MeasureSpec.makeMeasureSpec(layoutParams.width, MeasureSpec.EXACTLY);
	heightSpec = MeasureSpec.makeMeasureSpec(layoutParams.height, MeasureSpec.EXACTLY);
	view.measure(widthSpec, heightSpec);

	childWidth = view.getMeasuredWidth();
	childHeight = view.getMeasuredHeight();

	if (isVertical) {
	childTop -= childHeight + mMarginBottom;

	if (childTop < 0) {
	childTop += childHeight + mMarginBottom;
	break;
	}
	} else {
	childLeft -= childWidth + mMarginRight;

	if (childLeft < 0) {
	childLeft += childWidth + mMarginRight;
	break;
	}
	}

	addViewInLayout(view, -1, layoutParams);

	view.layout(childLeft, childTop, childLeft + childWidth, childTop + childHeight);

	if (isVertical) {
	childTop -= mMarginTop;
	} else {
	childLeft -= mMarginLeft;
	}
	}

	return isVertical ? childTop : childLeft;
	}

	private void removeAllApplications() {
	final int count = getChildCount();
	for (int i = count - 1; i >= 0; i--) {
	final View view = getChildAt(i);
	if (view != mButton) {
	removeViewAt(i);
	}
	}
	}

	private View createApplicationIcon(LayoutInflater inflater,
	ViewGroup group, ApplicationInfo info) {

	TextView textView = (TextView) inflater.inflate(R.layout.favorite, group, false);

	info.icon.setBounds(0, 0, mIconSize, mIconSize);
	textView.setCompoundDrawables(null, info.icon, null, null);
	textView.setText(info.title);

	textView.setTag(info.intent);
	textView.setOnClickListener(this);

	return textView;
	}

	/**
	* Sets the list of favorites.
	*
	* @param applications the applications to put in the favorites area
	*/
	public void setFavorites(List<ApplicationInfo> applications) {
	mFavorites = applications;
	requestLayout();
	}

	/**
	* Sets the list of recents.
	*
	* @param applications the applications to put in the recents area
	*/
	public void setRecents(List<ApplicationInfo> applications) {
	mRecents = applications;
	requestLayout();
	}

	public void onClick(View v) {
	getContext().startActivity((Intent) v.getTag());
	}
	}