/*
* 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);
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;
}
}
}