Change message body font size with slider, using new setTextZoom() WebView API, from 40% to 250%

res/layout/slider_preference_dialog.xml

@@ -0,0 +1,29 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<!--
+Copyright 2012 Jay Weisskopf
+
+Licensed under the MIT License (see LICENSE.txt)
+-->
+<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
+    android:id="@+id/slider_preference_layout"
+    android:layout_width="wrap_content"
+    android:layout_height="wrap_content"
+    android:orientation="vertical"
+    android:paddingBottom="8dip"
+    android:paddingLeft="16dip"
+    android:paddingRight="16dip"
+    android:paddingTop="8dip" >
+
+    <TextView
+        android:id="@+android:id/message"
+        android:layout_width="wrap_content"
+        android:layout_height="wrap_content" />
+
+    <SeekBar
+        android:id="@+id/slider_preference_seekbar"
+        android:layout_width="fill_parent"
+        android:layout_height="wrap_content"
+        android:paddingBottom="12dip"
+        android:paddingTop="12dip" />
+
+</LinearLayout>

res/values/attrs.xml

@@ -55,4 +55,8 @@
         <attr name="contactPictureFallbackDefaultBackgroundColor" format="reference|color"/>
     </declare-styleable>
 
+    <declare-styleable name="SliderPreference">
+        <attr name="android:summary" />
+    </declare-styleable>
+
 </resources>

res/xml/font_preferences.xml

@@ -153,6 +153,12 @@
             android:entryValues="@array/font_values_webview"
             android:dialogTitle="@string/font_size_message_view_content" />
 
+        <com.fsck.k9.activity.setup.SliderPreference
+            android:persistent="false"
+            android:key="message_view_content_font_slider"
+            android:title="@string/font_size_message_view_content"
+            android:dialogTitle="@string/font_size_message_view_content" />
+
     </PreferenceScreen>
 
     <PreferenceScreen

src/com/fsck/k9/FontSizes.java

@@ -28,6 +28,7 @@ public class FontSizes {
     private static final String MESSAGE_VIEW_SUBJECT = "fontSizeMessageViewSubject";
     private static final String MESSAGE_VIEW_DATE = "fontSizeMessageViewDate";
     private static final String MESSAGE_VIEW_CONTENT = "fontSizeMessageViewContent";
+    private static final String MESSAGE_VIEW_CONTENT_PERCENT = "fontSizeMessageViewContentPercent";
     private static final String MESSAGE_COMPOSE_INPUT = "fontSizeMessageComposeInput";
 
     /*
@@ -116,10 +117,18 @@ public class FontSizes {
     /**
      * Font size of the message content in the message view activity.
      *
-     * Note: The unit is WebSettings.TextSize
+     * Note: The unit is WebSettings.TextSize, this option is used only on Android 3.2 (API level 13) and below.
      */
     private TextSize messageViewContent = TextSize.NORMAL;
 
+
+    /**
+     * Font size of the message content in the message view activity, as percent from default size.
+     *
+     * Note: This option is used only on Android 4.0 (API level 14) and above.
+     */
+    private int messageViewContentPercent;
+
     /**
      * Font size for the input fields in the message compose activity.
      */
@@ -147,6 +156,7 @@ public class FontSizes {
         messageViewAdditionalHeaders = FONT_DEFAULT;
         messageViewSubject = FONT_DEFAULT;
         messageViewDate = FONT_DEFAULT;
+        messageViewContentPercent = 100;
 
         messageComposeInput = MEDIUM;
     }
@@ -175,6 +185,7 @@ public class FontSizes {
         editor.putInt(MESSAGE_VIEW_SUBJECT, messageViewSubject);
         editor.putInt(MESSAGE_VIEW_DATE, messageViewDate);
         editor.putInt(MESSAGE_VIEW_CONTENT, getMessageViewContentAsInt());
+        editor.putInt(MESSAGE_VIEW_CONTENT_PERCENT, getMessageViewContentAsPercent());
 
         editor.putInt(MESSAGE_COMPOSE_INPUT, messageComposeInput);
     }
@@ -203,6 +214,7 @@ public class FontSizes {
         messageViewSubject = prefs.getInt(MESSAGE_VIEW_SUBJECT, messageViewSubject);
         messageViewDate = prefs.getInt(MESSAGE_VIEW_DATE, messageViewDate);
         setMessageViewContent(prefs.getInt(MESSAGE_VIEW_CONTENT, 3));
+        setMessageViewContentAsPercent(prefs.getInt(MESSAGE_VIEW_CONTENT_PERCENT, 100));
 
         messageComposeInput = prefs.getInt(MESSAGE_COMPOSE_INPUT, messageComposeInput);
     }
@@ -359,6 +371,14 @@ public class FontSizes {
         }
     }
 
+    public int getMessageViewContentAsPercent() {
+        return messageViewContentPercent;
+    }
+
+    public void setMessageViewContentAsPercent(int size) {
+        messageViewContentPercent = size;
+    }
+
     public int getMessageComposeInput() {
         return messageComposeInput;
     }

src/com/fsck/k9/activity/setup/FontSizeSettings.java

@@ -19,6 +19,7 @@ public class FontSizeSettings extends K9PreferenceActivity {
     /*
      * Keys of the preferences defined in res/xml/font_preferences.xml
      */
+    private static final String PREFERENCE_SCREEN_MESSAGE_VIEW_FONTS = "message_view_fonts";
     private static final String PREFERENCE_ACCOUNT_NAME_FONT = "account_name_font";
     private static final String PREFERENCE_ACCOUNT_DESCRIPTION_FONT = "account_description_font";
     private static final String PREFERENCE_FOLDER_NAME_FONT = "folder_name_font";
@@ -34,6 +35,7 @@ public class FontSizeSettings extends K9PreferenceActivity {
     private static final String PREFERENCE_MESSAGE_VIEW_SUBJECT_FONT = "message_view_subject_font";
     private static final String PREFERENCE_MESSAGE_VIEW_DATE_FONT = "message_view_date_font";
     private static final String PREFERENCE_MESSAGE_VIEW_CONTENT_FONT = "message_view_content_font";
+    private static final String PREFERENCE_MESSAGE_VIEW_CONTENT_FONT_SLIDER = "message_view_content_font_slider";
     private static final String PREFERENCE_MESSAGE_COMPOSE_INPUT_FONT = "message_compose_input_font";
 
     private ListPreference mAccountName;
@@ -51,8 +53,11 @@ public class FontSizeSettings extends K9PreferenceActivity {
     private ListPreference mMessageViewSubject;
     private ListPreference mMessageViewDate;
     private ListPreference mMessageViewContent;
+    private SliderPreference mMessageViewContentSlider;
     private ListPreference mMessageComposeInput;
 
+    private static final int FONT_PERCENT_MIN = 40;
+    private static final int FONT_PERCENT_MAX = 250;
 
     /**
      * Start the FontSizeSettings activity.
@@ -120,6 +125,41 @@ public class FontSizeSettings extends K9PreferenceActivity {
                                   PREFERENCE_MESSAGE_VIEW_CONTENT_FONT,
                                   Integer.toString(fontSizes.getMessageViewContentAsInt()));
 
+        mMessageViewContentSlider = (SliderPreference) findPreference(
+                                  PREFERENCE_MESSAGE_VIEW_CONTENT_FONT_SLIDER);
+        // Scale to [0, 1]
+        mMessageViewContentSlider.setValue((float)
+                                  (fontSizes.getMessageViewContentAsPercent() - FONT_PERCENT_MIN) /
+                                  (FONT_PERCENT_MAX - FONT_PERCENT_MIN));
+        mMessageViewContentSlider.setOnPreferenceChangeListener(
+            new Preference.OnPreferenceChangeListener() {
+                // Show the preference value in the preference summary field.
+                @Override
+                public boolean onPreferenceChange(final Preference preference, final Object newValue) {
+                    final SliderPreference slider = (SliderPreference) preference;
+                    final Float value = (Float) newValue;
+                    // Scale from [0, 1]
+                    slider.setSummary(String.valueOf((int)(FONT_PERCENT_MIN +
+                                      value * (FONT_PERCENT_MAX - FONT_PERCENT_MIN))) + "%");
+                    slider.setDialogTitle(slider.getTitle() + " " + slider.getSummary());
+                    if (slider.getDialog() != null) {
+                        slider.getDialog().setTitle(slider.getDialogTitle());
+                    }
+                    return true;
+                }
+            }
+        );
+        mMessageViewContentSlider.getOnPreferenceChangeListener().onPreferenceChange(
+                                  mMessageViewContentSlider, new Float(mMessageViewContentSlider.getValue()));
+
+        if (android.os.Build.VERSION.SDK_INT >= android.os.Build.VERSION_CODES.ICE_CREAM_SANDWICH) {
+            ((PreferenceGroup) findPreference(PREFERENCE_SCREEN_MESSAGE_VIEW_FONTS)).
+                removePreference(mMessageViewContent);
+        } else {
+            ((PreferenceGroup) findPreference(PREFERENCE_SCREEN_MESSAGE_VIEW_FONTS)).
+                removePreference(mMessageViewContentSlider);
+        }
+
         mMessageComposeInput = setupListPreference(
                 PREFERENCE_MESSAGE_COMPOSE_INPUT_FONT,
                 Integer.toString(fontSizes.getMessageComposeInput()));
@@ -150,6 +190,10 @@ public class FontSizeSettings extends K9PreferenceActivity {
         fontSizes.setMessageViewSubject(Integer.parseInt(mMessageViewSubject.getValue()));
         fontSizes.setMessageViewDate(Integer.parseInt(mMessageViewDate.getValue()));
         fontSizes.setMessageViewContent(Integer.parseInt(mMessageViewContent.getValue()));
+        // Scale from [0, 1]
+        fontSizes.setMessageViewContentAsPercent((int)(FONT_PERCENT_MIN +
+                                mMessageViewContentSlider.getValue() *
+                                (FONT_PERCENT_MAX - FONT_PERCENT_MIN)));
 
         fontSizes.setMessageComposeInput(Integer.parseInt(mMessageComposeInput.getValue()));
 

src/com/fsck/k9/activity/setup/SliderPreference.java

@@ -0,0 +1,172 @@
+/*
+ * Copyright 2012 Jay Weisskopf
+ *
+ * Licensed under the MIT License (see LICENSE.txt)
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies
+ * of the Software, and to permit persons to whom the Software is furnished to do so,
+ * subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in all copies
+ * or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED,
+ * INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR
+ * PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE
+ * FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE,
+ * ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
+ *
+ * Source: https://github.com/jayschwa/AndroidSliderPreference
+ */
+
+package com.fsck.k9.activity.setup;
+
+import android.content.Context;
+import android.content.res.TypedArray;
+import android.preference.DialogPreference;
+import android.util.AttributeSet;
+import android.view.View;
+import android.widget.SeekBar;
+import com.fsck.k9.*;
+
+
+/**
+ * @author Jay Weisskopf
+ */
+public class SliderPreference extends DialogPreference {
+
+    protected final static int SEEKBAR_RESOLUTION = 10000;
+
+    protected float mValue;
+    protected int mSeekBarValue;
+    protected CharSequence[] mSummaries;
+
+    /**
+     * @param context
+     * @param attrs
+     */
+    public SliderPreference(Context context, AttributeSet attrs) {
+        super(context, attrs);
+        setup(context, attrs);
+    }
+
+    /**
+     * @param context
+     * @param attrs
+     * @param defStyle
+     */
+    public SliderPreference(Context context, AttributeSet attrs, int defStyle) {
+        super(context, attrs, defStyle);
+        setup(context, attrs);
+    }
+
+    private void setup(Context context, AttributeSet attrs) {
+        setDialogLayoutResource(R.layout.slider_preference_dialog);
+        TypedArray a = context.obtainStyledAttributes(attrs, R.styleable.SliderPreference);
+        try {
+            setSummary(a.getTextArray(R.styleable.SliderPreference_android_summary));
+        } catch (Exception e) {
+            // Do nothing
+        }
+        a.recycle();
+    }
+
+    @Override
+    protected Object onGetDefaultValue(TypedArray a, int index) {
+        return a.getFloat(index, 0);
+    }
+
+    @Override
+    protected void onSetInitialValue(boolean restoreValue, Object defaultValue) {
+        setValue(restoreValue ? getPersistedFloat(mValue) : (Float) defaultValue);
+    }
+
+    @Override
+    public CharSequence getSummary() {
+        if (mSummaries != null && mSummaries.length > 0) {
+            int index = (int) (mValue * mSummaries.length);
+            index = Math.min(index, mSummaries.length - 1);
+            return mSummaries[index];
+        } else {
+            return super.getSummary();
+        }
+    }
+
+    public void setSummary(CharSequence[] summaries) {
+        mSummaries = summaries;
+    }
+
+    @Override
+    public void setSummary(CharSequence summary) {
+        super.setSummary(summary);
+        mSummaries = null;
+    }
+
+    @Override
+    public void setSummary(int summaryResId) {
+        try {
+            setSummary(getContext().getResources().getStringArray(summaryResId));
+        } catch (Exception e) {
+            super.setSummary(summaryResId);
+        }
+    }
+
+    public float getValue() {
+        return mValue;
+    }
+
+    public void setValue(float value) {
+        value = Math.max(0, Math.min(value, 1)); // clamp to [0, 1]
+        if (shouldPersist()) {
+            persistFloat(value);
+        }
+        if (value != mValue) {
+            mValue = value;
+            notifyChanged();
+        }
+    }
+
+    @Override
+    protected View onCreateDialogView() {
+        mSeekBarValue = (int) (mValue * SEEKBAR_RESOLUTION);
+        View view = super.onCreateDialogView();
+        SeekBar seekbar = (SeekBar) view.findViewById(R.id.slider_preference_seekbar);
+        seekbar.setMax(SEEKBAR_RESOLUTION);
+        seekbar.setProgress(mSeekBarValue);
+        seekbar.setOnSeekBarChangeListener(new SeekBar.OnSeekBarChangeListener() {
+
+            @Override
+            public void onStopTrackingTouch(SeekBar seekBar) {
+            }
+
+            @Override
+            public void onStartTrackingTouch(SeekBar seekBar) {
+            }
+
+            @Override
+            public void onProgressChanged(SeekBar seekBar, int progress, boolean fromUser) {
+                if (fromUser) {
+                    SliderPreference.this.mSeekBarValue = progress;
+                    callChangeListener((float) SliderPreference.this.mSeekBarValue / SEEKBAR_RESOLUTION);
+                }
+            }
+        });
+        return view;
+    }
+
+    @Override
+    protected void onDialogClosed(boolean positiveResult) {
+        final float newValue = (float) mSeekBarValue / SEEKBAR_RESOLUTION;
+        if (positiveResult && callChangeListener(newValue)) {
+            setValue(newValue);
+        } else {
+            callChangeListener(mValue);
+        }
+        super.onDialogClosed(positiveResult);
+    }
+
+    // TODO: Save and restore preference state.
+}

src/com/fsck/k9/view/MessageWebView.java

@@ -109,7 +109,11 @@ public class MessageWebView extends RigidWebView {
 
         disableOverscrolling();
 
-        webSettings.setTextSize(K9.getFontSizes().getMessageViewContent());
+        if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.ICE_CREAM_SANDWICH) {
+            webSettings.setTextZoom(K9.getFontSizes().getMessageViewContentAsPercent());
+        } else {
+            webSettings.setTextSize(K9.getFontSizes().getMessageViewContent());
+        }
 
         // Disable network images by default.  This is overridden by preferences.
         blockNetworkData(true);