[Catalyst] Add MainSwitchBar.PreChangeListener

Bug: 335132588
Flag: EXEMPT library
Test: manual
Change-Id: Ib46675948770524813a5d9844a4ab5bab9bd3f23

1 files changed, 27 insertions, 2 deletions

diff --git a/packages/SettingsLib/MainSwitchPreference/src/com/android/settingslib/widget/MainSwitchBar.java b/packages/SettingsLib/MainSwitchPreference/src/com/android/settingslib/widget/MainSwitchBar.java
index 106802e9d1d1..c3594b8320c5 100644
--- a/packages/SettingsLib/MainSwitchPreference/src/com/android/settingslib/widget/MainSwitchBar.java
+++ b/packages/SettingsLib/MainSwitchPreference/src/com/android/settingslib/widget/MainSwitchBar.java
@@ -32,6 +32,7 @@ import android.widget.LinearLayout;
 import android.widget.TextView;
 
 import androidx.annotation.ColorInt;
+import androidx.annotation.Nullable;
 import androidx.annotation.RequiresApi;
 
 import com.android.settingslib.widget.mainswitch.R;
@@ -42,7 +43,7 @@ import java.util.List;
 /**
  * MainSwitchBar is a View with a customized Switch.
  * This component is used as the main switch of the page
- * to enable or disable the prefereces on the page.
+ * to enable or disable the preferences on the page.
  */
 public class MainSwitchBar extends LinearLayout implements OnCheckedChangeListener {
 
@@ -58,6 +59,8 @@ public class MainSwitchBar extends LinearLayout implements OnCheckedChangeListen
     protected CompoundButton mSwitch;
     private final View mFrameView;
 
+    private @Nullable PreChangeListener mPreChangeListener;
+
     public MainSwitchBar(Context context) {
         this(context, null);
     }
@@ -138,10 +141,20 @@ public class MainSwitchBar extends LinearLayout implements OnCheckedChangeListen
 
     @Override
     public boolean performClick() {
-        mSwitch.performClick();
+        if (callPreChangeListener()) {
+            mSwitch.performClick();
+        }
         return super.performClick();
     }
 
+    protected boolean callPreChangeListener() {
+        return mPreChangeListener == null || mPreChangeListener.preChange(!mSwitch.isChecked());
+    }
+
+    public void setPreChangeListener(@Nullable PreChangeListener preChangeListener) {
+        mPreChangeListener = preChangeListener;
+    }
+
     /**
      * Update the switch status
      */
@@ -341,4 +354,16 @@ public class MainSwitchBar extends LinearLayout implements OnCheckedChangeListen
 
         requestLayout();
     }
+
+    /**
+     * Listener callback before switch is toggled.
+     */
+    public interface PreChangeListener {
+        /**
+         * Returns if the new value can be set.
+         *
+         * When false is return, the switch toggle is not triggered at all.
+         */
+        boolean preChange(boolean isCheck);
+    }
 }