Add setting for configuring zoom level on double-tap.

Added a seek bar in Accessibility settings to configure the zoom level
on double-tap. The range is 75-125% with the default of 100% equal to
the display density.

Bug: 5312461
Change-Id: Iaf1b9f6f6659146db4031c5f819ef9cb55695b5c

3 files changed, 38 insertions, 0 deletions

diff --git a/src/com/android/browser/BrowserSettings.java b/src/com/android/browser/BrowserSettings.java
index 145178b..f92e53b 100644
--- a/src/com/android/browser/BrowserSettings.java
+++ b/src/com/android/browser/BrowserSettings.java
@@ -95,6 +95,11 @@ public class BrowserSettings implements OnSharedPreferenceChangeListener,
     private static final int TEXT_ZOOM_START_VAL = 10;
     // The size of a single step in the text zoom range, in percent
     private static final int TEXT_ZOOM_STEP = 5;
+    // The initial value in the double tap zoom range
+    // This is what represents 100% in the SeekBarPreference range
+    private static final int DOUBLE_TAP_ZOOM_START_VAL = 5;
+    // The size of a single step in the double tap zoom range, in percent
+    private static final int DOUBLE_TAP_ZOOM_STEP = 5;
 
     private static BrowserSettings sInstance;
 
@@ -248,6 +253,7 @@ public class BrowserSettings implements OnSharedPreferenceChangeListener,
         settings.setForceUserScalable(forceEnableUserScalable());
         settings.setPluginState(getPluginState());
         settings.setTextZoom(getTextZoom());
+        settings.setDoubleTapZoom(getDoubleTapZoom());
         settings.setAutoFillEnabled(isAutofillEnabled());
         settings.setLayoutAlgorithm(getLayoutAlgorithm());
         settings.setJavaScriptCanOpenWindowsAutomatically(!blockPopupWindows());
@@ -546,6 +552,15 @@ public class BrowserSettings implements OnSharedPreferenceChangeListener,
         return (percent - 100) / TEXT_ZOOM_STEP + TEXT_ZOOM_START_VAL;
     }
 
+    public int getAdjustedDoubleTapZoom(int rawValue) {
+        rawValue = (rawValue - DOUBLE_TAP_ZOOM_START_VAL) * DOUBLE_TAP_ZOOM_STEP;
+        return (int) ((rawValue + 100) * mFontSizeMult);
+    }
+
+    static int getRawDoubleTapZoom(int percent) {
+        return (percent - 100) / DOUBLE_TAP_ZOOM_STEP + DOUBLE_TAP_ZOOM_START_VAL;
+    }
+
     public SharedPreferences getPreferences() {
         return mPrefs;
     }
@@ -579,6 +594,16 @@ public class BrowserSettings implements OnSharedPreferenceChangeListener,
         mPrefs.edit().putInt(PREF_TEXT_ZOOM, getRawTextZoom(percent)).apply();
     }
 
+    public int getDoubleTapZoom() {
+        requireInitialization();
+        int doubleTapZoom = mPrefs.getInt(PREF_DOUBLE_TAP_ZOOM, 5);
+        return getAdjustedDoubleTapZoom(doubleTapZoom);
+    }
+
+    public void setDoubleTapZoom(int percent) {
+        mPrefs.edit().putInt(PREF_DOUBLE_TAP_ZOOM, getRawDoubleTapZoom(percent)).apply();
+    }
+
     // -----------------------------
     // getter/setters for advanced_preferences.xml
     // -----------------------------
diff --git a/src/com/android/browser/PreferenceKeys.java b/src/com/android/browser/PreferenceKeys.java
index 89fcbfc..15ccfe5 100644
--- a/src/com/android/browser/PreferenceKeys.java
+++ b/src/com/android/browser/PreferenceKeys.java
@@ -27,6 +27,7 @@ public interface PreferenceKeys {
     static final String PREF_MIN_FONT_SIZE = "min_font_size";
     static final String PREF_TEXT_SIZE = "text_size";
     static final String PREF_TEXT_ZOOM = "text_zoom";
+    static final String PREF_DOUBLE_TAP_ZOOM = "double_tap_zoom";
     static final String PREF_FORCE_USERSCALABLE = "force_userscalable";
     static final String PREF_INVERTED = "inverted";
     static final String PREF_INVERTED_CONTRAST = "inverted_contrast";
diff --git a/src/com/android/browser/preferences/AccessibilityPreferencesFragment.java b/src/com/android/browser/preferences/AccessibilityPreferencesFragment.java
index 6adfd23..c07c184 100644
--- a/src/com/android/browser/preferences/AccessibilityPreferencesFragment.java
+++ b/src/com/android/browser/preferences/AccessibilityPreferencesFragment.java
@@ -45,6 +45,9 @@ public class AccessibilityPreferencesFragment extends PreferenceFragment
         e = findPreference(PreferenceKeys.PREF_TEXT_ZOOM);
         e.setOnPreferenceChangeListener(this);
         updateTextZoomSummary(e, settings.getTextZoom());
+        e = findPreference(PreferenceKeys.PREF_DOUBLE_TAP_ZOOM);
+        e.setOnPreferenceChangeListener(this);
+        updateDoubleTapZoomSummary(e, settings.getDoubleTapZoom());
         e = findPreference(PreferenceKeys.PREF_INVERTED_CONTRAST);
         e.setOnPreferenceChangeListener(this);
         updateInvertedContrastSummary(e, (int) (settings.getInvertedContrast() * 100));
@@ -59,6 +62,10 @@ public class AccessibilityPreferencesFragment extends PreferenceFragment
         pref.setSummary(mFormat.format(textZoom / 100.0));
     }
 
+    void updateDoubleTapZoomSummary(Preference pref, int doubleTapZoom) {
+        pref.setSummary(mFormat.format(doubleTapZoom / 100.0));
+    }
+
     void updateInvertedContrastSummary(Preference pref, int contrast) {
         pref.setSummary(mFormat.format(contrast / 100.0));
     }
@@ -80,6 +87,11 @@ public class AccessibilityPreferencesFragment extends PreferenceFragment
             updateTextZoomSummary(pref, settings
                     .getAdjustedTextZoom((Integer) objValue));
         }
+        if (PreferenceKeys.PREF_DOUBLE_TAP_ZOOM.equals(pref.getKey())) {
+            BrowserSettings settings = BrowserSettings.getInstance();
+            updateDoubleTapZoomSummary(pref, settings
+                    .getAdjustedDoubleTapZoom((Integer) objValue));
+        }
         if (PreferenceKeys.PREF_INVERTED_CONTRAST.equals(pref.getKey())) {
             updateInvertedContrastSummary(pref,
                     (int) ((10 + (Integer) objValue) * 10));