The Tor Browser / file revision

 /* -*- 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.preferences;

 import org.mozilla.gecko.R;

 import android.app.AlertDialog;

 import android.content.Context;

 import android.content.res.Resources;

 import android.graphics.Color;

 import android.preference.DialogPreference;

 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() {

             @Override

             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() {

             @Override

             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;

     }

 }