src/com/android/browser/BreadCrumbView.java - platform/packages/apps/Browser - Git at Google

 /*
  * Copyright (C) 2010 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.browser;

 import android.content.Context;
 import android.content.res.TypedArray;
 import android.graphics.drawable.Drawable;
 import android.text.TextUtils;
 import android.util.AttributeSet;
 import android.util.TypedValue;
 import android.view.Gravity;
 import android.view.View;
 import android.view.View.OnClickListener;
 import android.widget.ImageButton;
 import android.widget.ImageView;
 import android.widget.LinearLayout;
 import android.widget.TextView;

 import java.util.ArrayList;
 import java.util.List;

 /**
  * Simple bread crumb view
  * Use setController to receive callbacks from user interactions
  * Use pushView, popView, clear, and getTopData to change/access the view stack
  */
 public class BreadCrumbView extends LinearLayout implements OnClickListener {
     private static final int DIVIDER_PADDING = 12; // dips
     private static final int CRUMB_PADDING = 8; // dips

     public interface Controller {
         public void onTop(BreadCrumbView view, int level, Object data);
     }

     private ImageButton mBackButton;
     private Controller mController;
     private List<Crumb> mCrumbs;
     private boolean mUseBackButton;
     private Drawable mSeparatorDrawable;
     private float mDividerPadding;
     private int mMaxVisible = -1;
     private Context mContext;
     private int mCrumbPadding;

     /**
      * @param context
      * @param attrs
      * @param defStyle
      */
     public BreadCrumbView(Context context, AttributeSet attrs, int defStyle) {
         super(context, attrs, defStyle);
         init(context);
     }

     /**
      * @param context
      * @param attrs
      */
     public BreadCrumbView(Context context, AttributeSet attrs) {
         super(context, attrs);
         init(context);
     }

     /**
      * @param context
      */
     public BreadCrumbView(Context context) {
         super(context);
         init(context);
     }

     private void init(Context ctx) {
         mContext = ctx;
         setFocusable(true);
         mUseBackButton = false;
         mCrumbs = new ArrayList<Crumb>();
         TypedArray a = mContext.obtainStyledAttributes(com.android.internal.R.styleable.Theme);
         mSeparatorDrawable = a.getDrawable(com.android.internal.R.styleable.Theme_dividerVertical);
         a.recycle();
         float density = mContext.getResources().getDisplayMetrics().density;
         mDividerPadding = DIVIDER_PADDING * density;
         mCrumbPadding = (int) (CRUMB_PADDING * density);
         addBackButton();
     }

     public void setUseBackButton(boolean useflag) {
         mUseBackButton = useflag;
         updateVisible();
     }

     public void setController(Controller ctl) {
         mController = ctl;
     }

     public int getMaxVisible() {
         return mMaxVisible;
     }

     public void setMaxVisible(int max) {
         mMaxVisible = max;
         updateVisible();
     }

     public int getTopLevel() {
         return mCrumbs.size();
     }

     public Object getTopData() {
         Crumb c = getTopCrumb();
         if (c != null) {
             return c.data;
         }
         return null;
     }

     public int size() {
         return mCrumbs.size();
     }

     public void clear() {
         while (mCrumbs.size() > 1) {
             pop(false);
         }
         pop(true);
     }

     public void notifyController() {
         if (mController != null) {
             if (mCrumbs.size() > 0) {
                 mController.onTop(this, mCrumbs.size(), getTopCrumb().data);
             } else {
                 mController.onTop(this, 0, null);
             }
         }
     }

     public View pushView(String name, Object data) {
         return pushView(name, true, data);
     }

     public View pushView(String name, boolean canGoBack, Object data) {
         Crumb crumb = new Crumb(name, canGoBack, data);
         pushCrumb(crumb);
         return crumb.crumbView;
     }

     public void pushView(View view, Object data) {
         Crumb crumb = new Crumb(view, true, data);
         pushCrumb(crumb);
     }

     public void popView() {
         pop(true);
     }

     private void addBackButton() {
         mBackButton = new ImageButton(mContext);
         mBackButton.setImageResource(R.drawable.ic_back_hierarchy_holo_dark);
         TypedValue outValue = new TypedValue();
         getContext().getTheme().resolveAttribute(
                 android.R.attr.selectableItemBackground, outValue, true);
         int resid = outValue.resourceId;
         mBackButton.setBackgroundResource(resid);
         mBackButton.setLayoutParams(new LayoutParams(LayoutParams.WRAP_CONTENT,
                 LayoutParams.MATCH_PARENT));
         mBackButton.setOnClickListener(this);
         mBackButton.setVisibility(View.GONE);
         mBackButton.setContentDescription(mContext.getText(
                 R.string.accessibility_button_bookmarks_folder_up));
         addView(mBackButton, 0);
     }

     private void pushCrumb(Crumb crumb) {
         if (mCrumbs.size() > 0) {
             addSeparator();
         }
         mCrumbs.add(crumb);
         addView(crumb.crumbView);
         updateVisible();
         crumb.crumbView.setOnClickListener(this);
     }

     private void addSeparator() {
         View sep = makeDividerView();
         sep.setLayoutParams(makeDividerLayoutParams());
         addView(sep);
     }

     private ImageView makeDividerView() {
         ImageView result = new ImageView(mContext);
         result.setImageDrawable(mSeparatorDrawable);
         result.setScaleType(ImageView.ScaleType.FIT_XY);
         return result;
     }

     private LayoutParams makeDividerLayoutParams() {
         LayoutParams params = new LayoutParams(LayoutParams.WRAP_CONTENT,
                 LayoutParams.MATCH_PARENT);
         params.topMargin = (int) mDividerPadding;
         params.bottomMargin = (int) mDividerPadding;
         return params;
     }

     private void pop(boolean notify) {
         int n = mCrumbs.size();
         if (n > 0) {
             removeLastView();
             if (!mUseBackButton || (n > 1)) {
                 // remove separator
                 removeLastView();
             }
             mCrumbs.remove(n - 1);
             if (mUseBackButton) {
                 Crumb top = getTopCrumb();
                 if (top != null && top.canGoBack) {
                     mBackButton.setVisibility(View.VISIBLE);
                 } else {
                     mBackButton.setVisibility(View.GONE);
                 }
             }
             updateVisible();
             if (notify) {
                 notifyController();
             }
         }
     }

     private void updateVisible() {
         // start at index 1 (0 == back button)
         int childIndex = 1;
         if (mMaxVisible >= 0) {
             int invisibleCrumbs = size() - mMaxVisible;
             if (invisibleCrumbs > 0) {
                 int crumbIndex = 0;
                 while (crumbIndex < invisibleCrumbs) {
                     // Set the crumb to GONE.
                     getChildAt(childIndex).setVisibility(View.GONE);
                     childIndex++;
                     // Each crumb is followed by a separator (except the last
                     // one).  Also make it GONE
                     if (getChildAt(childIndex) != null) {
                         getChildAt(childIndex).setVisibility(View.GONE);
                     }
                     childIndex++;
                     // Move to the next crumb.
                     crumbIndex++;
                 }
             }
             // Make sure the last two are visible.
             int childCount = getChildCount();
             while (childIndex < childCount) {
                 getChildAt(childIndex).setVisibility(View.VISIBLE);
                 childIndex++;
             }
         } else {
             int count = getChildCount();
             for (int i = childIndex; i < count ; i++) {
                 getChildAt(i).setVisibility(View.VISIBLE);
             }
         }
         if (mUseBackButton) {
             boolean canGoBack = getTopCrumb() != null ? getTopCrumb().canGoBack : false;
             mBackButton.setVisibility(canGoBack ? View.VISIBLE : View.GONE);
         } else {
             mBackButton.setVisibility(View.GONE);
         }
     }

     private void removeLastView() {
         int ix = getChildCount();
         if (ix > 0) {
             removeViewAt(ix-1);
         }
     }

     Crumb getTopCrumb() {
         Crumb crumb = null;
         if (mCrumbs.size() > 0) {
             crumb = mCrumbs.get(mCrumbs.size() - 1);
         }
         return crumb;
     }

     @Override
     public void onClick(View v) {
         if (mBackButton == v) {
             popView();
             notifyController();
         } else {
             // pop until view matches crumb view
             while (v != getTopCrumb().crumbView) {
                 pop(false);
             }
             notifyController();
         }
     }
     @Override
     public int getBaseline() {
         int ix = getChildCount();
         if (ix > 0) {
             // If there is at least one crumb, the baseline will be its
             // baseline.
             return getChildAt(ix-1).getBaseline();
         }
         return super.getBaseline();
     }

     @Override
     protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {
         super.onMeasure(widthMeasureSpec, heightMeasureSpec);
         int height = mSeparatorDrawable.getIntrinsicHeight();
         if (getMeasuredHeight() < height) {
             // This should only be an issue if there are currently no separators
             // showing; i.e. if there is one crumb and no back button.
             int mode = View.MeasureSpec.getMode(heightMeasureSpec);
             switch(mode) {
                 case View.MeasureSpec.AT_MOST:
                     if (View.MeasureSpec.getSize(heightMeasureSpec) < height) {
                         return;
                     }
                     break;
                 case View.MeasureSpec.EXACTLY:
                     return;
                 default:
                     break;
             }
             setMeasuredDimension(getMeasuredWidth(), height);
         }
     }

     class Crumb {

         public View crumbView;
         public boolean canGoBack;
         public Object data;

         public Crumb(String title, boolean backEnabled, Object tag) {
             init(makeCrumbView(title), backEnabled, tag);
         }

         public Crumb(View view, boolean backEnabled, Object tag) {
             init(view, backEnabled, tag);
         }

         private void init(View view, boolean back, Object tag) {
             canGoBack = back;
             crumbView = view;
             data = tag;
         }

         private TextView makeCrumbView(String name) {
             TextView tv = new TextView(mContext);
             tv.setTextAppearance(mContext, android.R.style.TextAppearance_Medium);
             tv.setPadding(mCrumbPadding, 0, mCrumbPadding, 0);
             tv.setGravity(Gravity.CENTER_VERTICAL);
             tv.setText(name);
             tv.setLayoutParams(new LayoutParams(LayoutParams.WRAP_CONTENT,
                     LayoutParams.MATCH_PARENT));
             tv.setSingleLine();
             tv.setEllipsize(TextUtils.TruncateAt.END);
             return tv;
         }

     }

 }
	/*
	* Copyright (C) 2010 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.browser;

	import android.content.Context;
	import android.content.res.TypedArray;
	import android.graphics.drawable.Drawable;
	import android.text.TextUtils;
	import android.util.AttributeSet;
	import android.util.TypedValue;
	import android.view.Gravity;
	import android.view.View;
	import android.view.View.OnClickListener;
	import android.widget.ImageButton;
	import android.widget.ImageView;
	import android.widget.LinearLayout;
	import android.widget.TextView;

	import java.util.ArrayList;
	import java.util.List;

	/**
	* Simple bread crumb view
	* Use setController to receive callbacks from user interactions
	* Use pushView, popView, clear, and getTopData to change/access the view stack
	*/
	public class BreadCrumbView extends LinearLayout implements OnClickListener {
	private static final int DIVIDER_PADDING = 12; // dips
	private static final int CRUMB_PADDING = 8; // dips

	public interface Controller {
	public void onTop(BreadCrumbView view, int level, Object data);
	}

	private ImageButton mBackButton;
	private Controller mController;
	private List<Crumb> mCrumbs;
	private boolean mUseBackButton;
	private Drawable mSeparatorDrawable;
	private float mDividerPadding;
	private int mMaxVisible = -1;
	private Context mContext;
	private int mCrumbPadding;

	/**
	* @param context
	* @param attrs
	* @param defStyle
	*/
	public BreadCrumbView(Context context, AttributeSet attrs, int defStyle) {
	super(context, attrs, defStyle);
	init(context);
	}

	/**
	* @param context
	* @param attrs
	*/
	public BreadCrumbView(Context context, AttributeSet attrs) {
	super(context, attrs);
	init(context);
	}

	/**
	* @param context
	*/
	public BreadCrumbView(Context context) {
	super(context);
	init(context);
	}

	private void init(Context ctx) {
	mContext = ctx;
	setFocusable(true);
	mUseBackButton = false;
	mCrumbs = new ArrayList<Crumb>();
	TypedArray a = mContext.obtainStyledAttributes(com.android.internal.R.styleable.Theme);
	mSeparatorDrawable = a.getDrawable(com.android.internal.R.styleable.Theme_dividerVertical);
	a.recycle();
	float density = mContext.getResources().getDisplayMetrics().density;
	mDividerPadding = DIVIDER_PADDING * density;
	mCrumbPadding = (int) (CRUMB_PADDING * density);
	addBackButton();
	}

	public void setUseBackButton(boolean useflag) {
	mUseBackButton = useflag;
	updateVisible();
	}

	public void setController(Controller ctl) {
	mController = ctl;
	}

	public int getMaxVisible() {
	return mMaxVisible;
	}

	public void setMaxVisible(int max) {
	mMaxVisible = max;
	updateVisible();
	}

	public int getTopLevel() {
	return mCrumbs.size();
	}

	public Object getTopData() {
	Crumb c = getTopCrumb();
	if (c != null) {
	return c.data;
	}
	return null;
	}

	public int size() {
	return mCrumbs.size();
	}

	public void clear() {
	while (mCrumbs.size() > 1) {
	pop(false);
	}
	pop(true);
	}

	public void notifyController() {
	if (mController != null) {
	if (mCrumbs.size() > 0) {
	mController.onTop(this, mCrumbs.size(), getTopCrumb().data);
	} else {
	mController.onTop(this, 0, null);
	}
	}
	}

	public View pushView(String name, Object data) {
	return pushView(name, true, data);
	}

	public View pushView(String name, boolean canGoBack, Object data) {
	Crumb crumb = new Crumb(name, canGoBack, data);
	pushCrumb(crumb);
	return crumb.crumbView;
	}

	public void pushView(View view, Object data) {
	Crumb crumb = new Crumb(view, true, data);
	pushCrumb(crumb);
	}

	public void popView() {
	pop(true);
	}

	private void addBackButton() {
	mBackButton = new ImageButton(mContext);
	mBackButton.setImageResource(R.drawable.ic_back_hierarchy_holo_dark);
	TypedValue outValue = new TypedValue();
	getContext().getTheme().resolveAttribute(
	android.R.attr.selectableItemBackground, outValue, true);
	int resid = outValue.resourceId;
	mBackButton.setBackgroundResource(resid);
	mBackButton.setLayoutParams(new LayoutParams(LayoutParams.WRAP_CONTENT,
	LayoutParams.MATCH_PARENT));
	mBackButton.setOnClickListener(this);
	mBackButton.setVisibility(View.GONE);
	mBackButton.setContentDescription(mContext.getText(
	R.string.accessibility_button_bookmarks_folder_up));
	addView(mBackButton, 0);
	}

	private void pushCrumb(Crumb crumb) {
	if (mCrumbs.size() > 0) {
	addSeparator();
	}
	mCrumbs.add(crumb);
	addView(crumb.crumbView);
	updateVisible();
	crumb.crumbView.setOnClickListener(this);
	}

	private void addSeparator() {
	View sep = makeDividerView();
	sep.setLayoutParams(makeDividerLayoutParams());
	addView(sep);
	}

	private ImageView makeDividerView() {
	ImageView result = new ImageView(mContext);
	result.setImageDrawable(mSeparatorDrawable);
	result.setScaleType(ImageView.ScaleType.FIT_XY);
	return result;
	}

	private LayoutParams makeDividerLayoutParams() {
	LayoutParams params = new LayoutParams(LayoutParams.WRAP_CONTENT,
	LayoutParams.MATCH_PARENT);
	params.topMargin = (int) mDividerPadding;
	params.bottomMargin = (int) mDividerPadding;
	return params;
	}

	private void pop(boolean notify) {
	int n = mCrumbs.size();
	if (n > 0) {
	removeLastView();
	if (!mUseBackButton \|\| (n > 1)) {
	// remove separator
	removeLastView();
	}
	mCrumbs.remove(n - 1);
	if (mUseBackButton) {
	Crumb top = getTopCrumb();
	if (top != null && top.canGoBack) {
	mBackButton.setVisibility(View.VISIBLE);
	} else {
	mBackButton.setVisibility(View.GONE);
	}
	}
	updateVisible();
	if (notify) {
	notifyController();
	}
	}
	}

	private void updateVisible() {
	// start at index 1 (0 == back button)
	int childIndex = 1;
	if (mMaxVisible >= 0) {
	int invisibleCrumbs = size() - mMaxVisible;
	if (invisibleCrumbs > 0) {
	int crumbIndex = 0;
	while (crumbIndex < invisibleCrumbs) {
	// Set the crumb to GONE.
	getChildAt(childIndex).setVisibility(View.GONE);
	childIndex++;
	// Each crumb is followed by a separator (except the last
	// one). Also make it GONE
	if (getChildAt(childIndex) != null) {
	getChildAt(childIndex).setVisibility(View.GONE);
	}
	childIndex++;
	// Move to the next crumb.
	crumbIndex++;
	}
	}
	// Make sure the last two are visible.
	int childCount = getChildCount();
	while (childIndex < childCount) {
	getChildAt(childIndex).setVisibility(View.VISIBLE);
	childIndex++;
	}
	} else {
	int count = getChildCount();
	for (int i = childIndex; i < count ; i++) {
	getChildAt(i).setVisibility(View.VISIBLE);
	}
	}
	if (mUseBackButton) {
	boolean canGoBack = getTopCrumb() != null ? getTopCrumb().canGoBack : false;
	mBackButton.setVisibility(canGoBack ? View.VISIBLE : View.GONE);
	} else {
	mBackButton.setVisibility(View.GONE);
	}
	}

	private void removeLastView() {
	int ix = getChildCount();
	if (ix > 0) {
	removeViewAt(ix-1);
	}
	}

	Crumb getTopCrumb() {
	Crumb crumb = null;
	if (mCrumbs.size() > 0) {
	crumb = mCrumbs.get(mCrumbs.size() - 1);
	}
	return crumb;
	}

	@Override
	public void onClick(View v) {
	if (mBackButton == v) {
	popView();
	notifyController();
	} else {
	// pop until view matches crumb view
	while (v != getTopCrumb().crumbView) {
	pop(false);
	}
	notifyController();
	}
	}
	@Override
	public int getBaseline() {
	int ix = getChildCount();
	if (ix > 0) {
	// If there is at least one crumb, the baseline will be its
	// baseline.
	return getChildAt(ix-1).getBaseline();
	}
	return super.getBaseline();
	}

	@Override
	protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {
	super.onMeasure(widthMeasureSpec, heightMeasureSpec);
	int height = mSeparatorDrawable.getIntrinsicHeight();
	if (getMeasuredHeight() < height) {
	// This should only be an issue if there are currently no separators
	// showing; i.e. if there is one crumb and no back button.
	int mode = View.MeasureSpec.getMode(heightMeasureSpec);
	switch(mode) {
	case View.MeasureSpec.AT_MOST:
	if (View.MeasureSpec.getSize(heightMeasureSpec) < height) {
	return;
	}
	break;
	case View.MeasureSpec.EXACTLY:
	return;
	default:
	break;
	}
	setMeasuredDimension(getMeasuredWidth(), height);
	}
	}

	class Crumb {

	public View crumbView;
	public boolean canGoBack;
	public Object data;

	public Crumb(String title, boolean backEnabled, Object tag) {
	init(makeCrumbView(title), backEnabled, tag);
	}

	public Crumb(View view, boolean backEnabled, Object tag) {
	init(view, backEnabled, tag);
	}

	private void init(View view, boolean back, Object tag) {
	canGoBack = back;
	crumbView = view;
	data = tag;
	}

	private TextView makeCrumbView(String name) {
	TextView tv = new TextView(mContext);
	tv.setTextAppearance(mContext, android.R.style.TextAppearance_Medium);
	tv.setPadding(mCrumbPadding, 0, mCrumbPadding, 0);
	tv.setGravity(Gravity.CENTER_VERTICAL);
	tv.setText(name);
	tv.setLayoutParams(new LayoutParams(LayoutParams.WRAP_CONTENT,
	LayoutParams.MATCH_PARENT));
	tv.setSingleLine();
	tv.setEllipsize(TextUtils.TruncateAt.END);
	return tv;
	}

	}

	}