Add the settings content observer for shortcut preference.

Root cause:
Didn't update the UI when settings value chagned.

Next:
Add the settings content observer.

Bug: 155837154
Test: manual test
Change-Id: Icee0bb50f88987ea6c8a0be59bd936628a32ca1e

src/com/android/settings/accessibility/ToggleFeaturePreferenceFragment.java

@@ -30,6 +30,7 @@ import android.content.pm.ResolveInfo;
 import android.graphics.drawable.Drawable;
 import android.net.Uri;
 import android.os.Bundle;
+import android.os.Handler;
 import android.os.UserHandle;
 import android.provider.Settings;
 import android.text.Html;
@@ -96,6 +97,7 @@ public abstract class ToggleFeaturePreferenceFragment extends SettingsPreference
     private int mUserShortcutTypes = UserShortcutType.EMPTY;
     private CheckBox mSoftwareTypeCheckBox;
     private CheckBox mHardwareTypeCheckBox;
+    private SettingsContentObserver mSettingsContentObserver;
 
     // For html description of accessibility service, must follow the rule, such as
     // <img src="R.drawable.fileName"/>, a11y settings will get the resources successfully.
@@ -133,6 +135,17 @@ public abstract class ToggleFeaturePreferenceFragment extends SettingsPreference
             removeDialog(DialogEnums.EDIT_SHORTCUT);
             mShortcutPreference.setSummary(getShortcutTypeSummary(getPrefContext()));
         };
+
+        final List<String> shortcutFeatureKeys = new ArrayList<>();
+        shortcutFeatureKeys.add(Settings.Secure.ACCESSIBILITY_BUTTON_TARGETS);
+        shortcutFeatureKeys.add(Settings.Secure.ACCESSIBILITY_SHORTCUT_TARGET_SERVICE);
+        mSettingsContentObserver = new SettingsContentObserver(new Handler(), shortcutFeatureKeys) {
+            @Override
+            public void onChange(boolean selfChange, Uri uri) {
+                updateShortcutPreferenceData();
+                updateShortcutPreference();
+            }
+        };
         return super.onCreateView(inflater, container, savedInstanceState);
     }
 
@@ -229,6 +242,7 @@ public abstract class ToggleFeaturePreferenceFragment extends SettingsPreference
         final AccessibilityManager am = getPrefContext().getSystemService(
                 AccessibilityManager.class);
         am.addTouchExplorationStateChangeListener(mTouchExplorationStateChangeListener);
+        mSettingsContentObserver.register(getContentResolver());
         updateShortcutPreferenceData();
         updateShortcutPreference();
     }
@@ -238,6 +252,7 @@ public abstract class ToggleFeaturePreferenceFragment extends SettingsPreference
         final AccessibilityManager am = getPrefContext().getSystemService(
                 AccessibilityManager.class);
         am.removeTouchExplorationStateChangeListener(mTouchExplorationStateChangeListener);
+        mSettingsContentObserver.unregister(getContentResolver());
         super.onPause();
     }
 
@@ -618,7 +633,7 @@ public abstract class ToggleFeaturePreferenceFragment extends SettingsPreference
                 getShortcutTypeSummary(getPrefContext()));
     }
 
-    private void updateShortcutPreferenceData() {
+    protected void updateShortcutPreferenceData() {
         if (mComponentName == null) {
             return;
         }
@@ -651,7 +666,7 @@ public abstract class ToggleFeaturePreferenceFragment extends SettingsPreference
         mShortcutPreference.setTitle(title);
     }
 
-    private void updateShortcutPreference() {
+    protected void updateShortcutPreference() {
         if (mComponentName == null) {
             return;
         }

src/com/android/settings/accessibility/ToggleScreenMagnificationPreferenceFragment.java

@@ -467,7 +467,8 @@ public class ToggleScreenMagnificationPreferenceFragment extends
         showDialog(DialogEnums.MAGNIFICATION_EDIT_SHORTCUT);
     }
 
-    private void updateShortcutPreferenceData() {
+    @Override
+    protected void updateShortcutPreferenceData() {
         // Get the user shortcut type from settings provider.
         mUserShortcutType = getUserShortcutTypeFromSettings(getPrefContext());
         if (mUserShortcutType != UserShortcutType.EMPTY) {
@@ -489,7 +490,8 @@ public class ToggleScreenMagnificationPreferenceFragment extends
         mShortcutPreference.setTitle(title);
     }
 
-    private void updateShortcutPreference() {
+    @Override
+    protected void updateShortcutPreference() {
         final int shortcutTypes = getUserShortcutTypes(getPrefContext(), UserShortcutType.SOFTWARE);
         mShortcutPreference.setChecked(
                 hasMagnificationValuesInSettings(getPrefContext(), shortcutTypes));