gecko/mobile/android/base/FontSizePreference.java

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/* -*- Mode: Java; c-basic-offset: 4; tab-width: 4; indent-tabs-mode: nil; -*-
* This Source Code Form is subject to the terms of the Mozilla Public
* License, v. 2.0. If a copy of the MPL was not distributed with this
* file, You can obtain one at http://mozilla.org/MPL/2.0/. */
package org.mozilla.gecko;
import android.app.AlertDialog;
import android.content.Context;
import android.content.res.Resources;
import android.graphics.Color;
import android.preference.DialogPreference;
import android.preference.Preference.OnPreferenceChangeListener;
import android.util.AttributeSet;
import android.util.Log;
import android.util.TypedValue;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.Button;
import android.widget.ScrollView;
import android.widget.TextView;
import java.util.HashMap;
class FontSizePreference extends DialogPreference {
private static final String LOGTAG = "FontSizePreference";
private static final int TWIP_TO_PT_RATIO = 20; // 20 twip = 1 point.
private static final int PREVIEW_FONT_SIZE_UNIT = TypedValue.COMPLEX_UNIT_PT;
private static final int DEFAULT_FONT_INDEX = 2;
private final Context mContext;
/** Container for mPreviewFontView to allow for scrollable padding at the top of the view. */
private ScrollView mScrollingContainer;
private TextView mPreviewFontView;
private Button mIncreaseFontButton;
private Button mDecreaseFontButton;
private final String[] mFontTwipValues;
private final String[] mFontSizeNames; // Ex: "Small".
/** Index into the above arrays for the saved preference value (from Gecko). */
private int mSavedFontIndex = DEFAULT_FONT_INDEX;
/** Index into the above arrays for the currently displayed font size (the preview). */
private int mPreviewFontIndex = mSavedFontIndex;
private final HashMap<String, Integer> mFontTwipToIndexMap;
public FontSizePreference(Context context, AttributeSet attrs) {
super(context, attrs);
mContext = context;
final Resources res = mContext.getResources();
mFontTwipValues = res.getStringArray(R.array.pref_font_size_values);
mFontSizeNames = res.getStringArray(R.array.pref_font_size_entries);
mFontTwipToIndexMap = new HashMap<String, Integer>();
for (int i = 0; i < mFontTwipValues.length; ++i) {
mFontTwipToIndexMap.put(mFontTwipValues[i], i);
}
}
@Override
protected void onPrepareDialogBuilder(AlertDialog.Builder builder) {
final LayoutInflater inflater =
(LayoutInflater) mContext.getSystemService(Context.LAYOUT_INFLATER_SERVICE);
View dialogView = inflater.inflate(R.layout.font_size_preference, null);
initInternalViews(dialogView);
updatePreviewFontSize(mFontTwipValues[mPreviewFontIndex]);
builder.setTitle(null);
builder.setView(dialogView);
}
/** Saves relevant views to instance variables and initializes their settings. */
private void initInternalViews(View dialogView) {
mScrollingContainer = (ScrollView) dialogView.findViewById(R.id.scrolling_container);
// Background cannot be set in XML (see bug 783597 - TODO: Change this to XML when bug is fixed).
mScrollingContainer.setBackgroundColor(Color.WHITE);
mPreviewFontView = (TextView) dialogView.findViewById(R.id.preview);
mDecreaseFontButton = (Button) dialogView.findViewById(R.id.decrease_preview_font_button);
mIncreaseFontButton = (Button) dialogView.findViewById(R.id.increase_preview_font_button);
setButtonState(mPreviewFontIndex);
mDecreaseFontButton.setOnClickListener(new View.OnClickListener() {
public void onClick(View v) {
mPreviewFontIndex = Math.max(mPreviewFontIndex - 1, 0);
updatePreviewFontSize(mFontTwipValues[mPreviewFontIndex]);
mIncreaseFontButton.setEnabled(true);
// If we reached the minimum index, disable the button.
if (mPreviewFontIndex == 0) {
mDecreaseFontButton.setEnabled(false);
}
}
});
mIncreaseFontButton.setOnClickListener(new View.OnClickListener() {
public void onClick(View v) {
mPreviewFontIndex = Math.min(mPreviewFontIndex + 1, mFontTwipValues.length - 1);
updatePreviewFontSize(mFontTwipValues[mPreviewFontIndex]);
mDecreaseFontButton.setEnabled(true);
// If we reached the maximum index, disable the button.
if (mPreviewFontIndex == mFontTwipValues.length - 1) {
mIncreaseFontButton.setEnabled(false);
}
}
});
}
@Override
protected void onDialogClosed(boolean positiveResult) {
super.onDialogClosed(positiveResult);
if (!positiveResult) {
mPreviewFontIndex = mSavedFontIndex;
return;
}
mSavedFontIndex = mPreviewFontIndex;
final String twipVal = mFontTwipValues[mSavedFontIndex];
final OnPreferenceChangeListener prefChangeListener = getOnPreferenceChangeListener();
if (prefChangeListener == null) {
Log.e(LOGTAG, "PreferenceChangeListener is null. FontSizePreference will not be saved to Gecko.");
return;
}
prefChangeListener.onPreferenceChange(this, twipVal);
}
/**
* Finds the index of the given twip value and sets it as the saved preference value. Also the
* current preview text size to the given value. Does not update the mPreviewFontView text size.
*/
protected void setSavedFontSize(String twip) {
final Integer index = mFontTwipToIndexMap.get(twip);
if (index != null) {
mSavedFontIndex = index;
mPreviewFontIndex = mSavedFontIndex;
return;
}
resetSavedFontSizeToDefault();
Log.e(LOGTAG, "setSavedFontSize: Given font size does not exist in twip values map. Reverted to default font size.");
}
/**
* Updates the mPreviewFontView to the given text size, resets the container's scroll to the top
* left, and invalidates the view. Does not update the font indices.
*/
private void updatePreviewFontSize(String twip) {
float pt = convertTwipStrToPT(twip);
// Android will not render a font size of 0 pt but for Gecko, 0 twip turns off font
// inflation. Thus we special case 0 twip to display a renderable font size.
if (pt == 0) {
// Android adds an inexplicable extra margin on the smallest font size so to get around
// this, we reinflate the view.
ViewGroup parentView = (ViewGroup) mScrollingContainer.getParent();
parentView.removeAllViews();
final LayoutInflater inflater =
(LayoutInflater) mContext.getSystemService(Context.LAYOUT_INFLATER_SERVICE);
View dialogView = inflater.inflate(R.layout.font_size_preference, parentView);
initInternalViews(dialogView);
mPreviewFontView.setTextSize(PREVIEW_FONT_SIZE_UNIT, 1);
} else {
mPreviewFontView.setTextSize(PREVIEW_FONT_SIZE_UNIT, pt);
}
mScrollingContainer.scrollTo(0, 0);
}
/**
* Resets the font indices to the default value. Does not update the mPreviewFontView text size.
*/
private void resetSavedFontSizeToDefault() {
mSavedFontIndex = DEFAULT_FONT_INDEX;
mPreviewFontIndex = mSavedFontIndex;
}
private void setButtonState(int index) {
if (index == 0) {
mDecreaseFontButton.setEnabled(false);
} else if (index == mFontTwipValues.length - 1) {
mIncreaseFontButton.setEnabled(false);
}
}
/**
* Returns the name of the font size (ex: "Small") at the currently saved preference value.
*/
protected String getSavedFontSizeName() {
return mFontSizeNames[mSavedFontIndex];
}
private float convertTwipStrToPT(String twip) {
return Float.parseFloat(twip) / TWIP_TO_PT_RATIO;
}
}