[Android] Extract helper methods from ManagedPreferenceDelegate

A follow-up to https://crrev.com/c/1047870.

This CL removes initPreference, onBindViewToPreference and
onClickPreference helper methods from ManagedPreferenceDelegate
interface, adding corresponding static methods to
ManagedPreferencesUtils instead. It also moves null checks into these
methods, making ManagedPreferenceDelegate param @Nullable.

Bug: None
Change-Id: I53e3669962c21e68a00b83dcde38b229d0b44364
Reviewed-on: https://chromium-review.googlesource.com/1057472Reviewed-by: Bernhard Bauer <bauerb@chromium.org>
Commit-Queue: Boris Sazonov <bsazonov@chromium.org>
Cr-Commit-Position: refs/heads/master@{#558657}

chrome/android/java/src/org/chromium/chrome/browser/preferences/ChromeBaseCheckBoxPreference.java

@@ -29,19 +29,19 @@ public class ChromeBaseCheckBoxPreference extends CheckBoxPreference {
      */
     public void setManagedPreferenceDelegate(ManagedPreferenceDelegate delegate) {
         mManagedPrefDelegate = delegate;
-        if (mManagedPrefDelegate != null) mManagedPrefDelegate.initPreference(this);
+        ManagedPreferencesUtils.initPreference(mManagedPrefDelegate, this);
     }
 
     @Override
     protected void onBindView(View view) {
         super.onBindView(view);
         ((TextView) view.findViewById(android.R.id.title)).setSingleLine(false);
-        if (mManagedPrefDelegate != null) mManagedPrefDelegate.onBindViewToPreference(this, view);
+        ManagedPreferencesUtils.onBindViewToPreference(mManagedPrefDelegate, this, view);
     }
 
     @Override
     protected void onClick() {
-        if (mManagedPrefDelegate != null && mManagedPrefDelegate.onClickPreference(this)) return;
+        if (ManagedPreferencesUtils.onClickPreference(mManagedPrefDelegate, this)) return;
         super.onClick();
     }
 }

chrome/android/java/src/org/chromium/chrome/browser/preferences/ChromeBaseListPreference.java

@@ -31,19 +31,19 @@ public class ChromeBaseListPreference extends ListPreference {
      */
     public void setManagedPreferenceDelegate(ManagedPreferenceDelegate delegate) {
         mManagedPrefDelegate = delegate;
-        if (mManagedPrefDelegate != null) mManagedPrefDelegate.initPreference(this);
+        ManagedPreferencesUtils.initPreference(mManagedPrefDelegate, this);
     }
 
     @Override
     protected void onBindView(View view) {
         super.onBindView(view);
         ((TextView) view.findViewById(android.R.id.title)).setSingleLine(false);
-        if (mManagedPrefDelegate != null) mManagedPrefDelegate.onBindViewToPreference(this, view);
+        ManagedPreferencesUtils.onBindViewToPreference(mManagedPrefDelegate, this, view);
     }
 
     @Override
     protected void onClick() {
-        if (mManagedPrefDelegate != null && mManagedPrefDelegate.onClickPreference(this)) return;
+        if (ManagedPreferencesUtils.onClickPreference(mManagedPrefDelegate, this)) return;
         super.onClick();
     }
 

chrome/android/java/src/org/chromium/chrome/browser/preferences/ChromeBasePreference.java

@@ -41,19 +41,19 @@ public class ChromeBasePreference extends Preference {
      */
     public void setManagedPreferenceDelegate(ManagedPreferenceDelegate delegate) {
         mManagedPrefDelegate = delegate;
-        if (mManagedPrefDelegate != null) mManagedPrefDelegate.initPreference(this);
+        ManagedPreferencesUtils.initPreference(mManagedPrefDelegate, this);
     }
 
     @Override
     protected void onBindView(View view) {
         super.onBindView(view);
         ((TextView) view.findViewById(android.R.id.title)).setSingleLine(false);
-        if (mManagedPrefDelegate != null) mManagedPrefDelegate.onBindViewToPreference(this, view);
+        ManagedPreferencesUtils.onBindViewToPreference(mManagedPrefDelegate, this, view);
     }
 
     @Override
     protected void onClick() {
-        if (mManagedPrefDelegate != null && mManagedPrefDelegate.onClickPreference(this)) return;
+        if (ManagedPreferencesUtils.onClickPreference(mManagedPrefDelegate, this)) return;
         super.onClick();
     }
 }

chrome/android/java/src/org/chromium/chrome/browser/preferences/ChromeSwitchPreference.java

@@ -47,7 +47,7 @@ public class ChromeSwitchPreference extends SwitchPreference {
      */
     public void setManagedPreferenceDelegate(ManagedPreferenceDelegate delegate) {
         mManagedPrefDelegate = delegate;
-        if (mManagedPrefDelegate != null) mManagedPrefDelegate.initPreference(this);
+        ManagedPreferencesUtils.initPreference(mManagedPrefDelegate, this);
     }
 
     /**
@@ -90,12 +90,12 @@ public class ChromeSwitchPreference extends SwitchPreference {
             summary.setVisibility(View.GONE);
         }
 
-        if (mManagedPrefDelegate != null) mManagedPrefDelegate.onBindViewToPreference(this, view);
+        ManagedPreferencesUtils.onBindViewToPreference(mManagedPrefDelegate, this, view);
     }
 
     @Override
     protected void onClick() {
-        if (mManagedPrefDelegate != null && mManagedPrefDelegate.onClickPreference(this)) return;
+        if (ManagedPreferencesUtils.onClickPreference(mManagedPrefDelegate, this)) return;
         super.onClick();
     }
 }

chrome/android/java/src/org/chromium/chrome/browser/preferences/ManagedPreferenceDelegate.java

@@ -5,10 +5,6 @@
 package org.chromium.chrome.browser.preferences;
 
 import android.preference.Preference;
-import android.view.View;
-
-import org.chromium.chrome.R;
-import org.chromium.chrome.browser.util.ViewUtils;
 
 /**
  * A delegate that determines whether a Preference is managed by enterprise policy. This is used
@@ -56,72 +52,7 @@ public interface ManagedPreferenceDelegate {
      */
     // TODO(bauerb): Rename to isPreferenceClickDisabled.
     default boolean isPreferenceClickDisabledByPolicy(Preference preference) {
-        return isPreferenceControlledByPolicy(preference) ||
-                isPreferenceControlledByCustodian(preference);
-    }
-
-    /**
-     * Initializes the Preference based on the state of any policies that may affect it,
-     * e.g. by showing a managed icon or disabling clicks on the preference.
-     *
-     * This should be called once, before the preference is displayed.
-     */
-    default void initPreference(Preference preference) {
-        if (isPreferenceControlledByPolicy(preference)) {
-            preference.setIcon(ManagedPreferencesUtils.getManagedByEnterpriseIconId());
-        } else if (isPreferenceControlledByCustodian(preference)) {
-            preference.setIcon(R.drawable.ic_account_child_grey600_36dp);
-        }
-
-        if (isPreferenceClickDisabledByPolicy(preference)) {
-            // Disable the views and prevent the Preference from mucking with the enabled state.
-            preference.setShouldDisableView(false);
-
-            // Prevent default click behavior.
-            preference.setFragment(null);
-            preference.setIntent(null);
-            preference.setOnPreferenceClickListener(null);
-        }
-    }
-
-    /**
-     * Disables the Preference's views if the preference is not clickable.
-     *
-     * Note: this disables the View instead of disabling the Preference, so that the Preference
-     * still receives click events, which will trigger a "Managed by your administrator" toast.
-     *
-     * This should be called from the Preference's onBindView() method.
-     *
-     * @param preference The Preference that owns the view
-     * @param view The View that was bound to the Preference
-     */
-    default void onBindViewToPreference(Preference preference, View view) {
-        if (isPreferenceClickDisabledByPolicy(preference)) {
-            ViewUtils.setEnabledRecursive(view, false);
-        }
-    }
-
-    /**
-     * Intercepts the click event if the given Preference is managed and shows a toast in that case.
-     *
-     * This should be called from the Preference's onClick() method.
-     *
-     * @param preference The Preference that was clicked.
-     * @return true if the click event was handled by this helper and shouldn't be further
-     *         propagated; false otherwise.
-     */
-    default boolean onClickPreference(Preference preference) {
-        if (!isPreferenceClickDisabledByPolicy(preference)) return false;
-
-        if (isPreferenceControlledByPolicy(preference)) {
-            ManagedPreferencesUtils.showManagedByAdministratorToast(preference.getContext());
-        } else if (isPreferenceControlledByCustodian(preference)) {
-            ManagedPreferencesUtils.showManagedByParentToast(preference.getContext());
-        } else {
-            // If the preference is disabled, it should be either because it's managed by enterprise
-            // policy or by the custodian.
-            assert false;
-        }
-        return true;
+        return isPreferenceControlledByPolicy(preference)
+                || isPreferenceControlledByCustodian(preference);
     }
 }
\ No newline at end of file

chrome/android/java/src/org/chromium/chrome/browser/preferences/ManagedPreferencesUtils.java

@@ -5,8 +5,12 @@
 package org.chromium.chrome.browser.preferences;
 
 import android.content.Context;
+import android.preference.Preference;
+import android.support.annotation.Nullable;
+import android.view.View;
 
 import org.chromium.chrome.R;
+import org.chromium.chrome.browser.util.ViewUtils;
 import org.chromium.ui.widget.Toast;
 
 /**
@@ -46,4 +50,84 @@ public class ManagedPreferencesUtils {
     public static int getManagedByEnterpriseIconId() {
         return R.drawable.controlled_setting_mandatory;
     }
+
+    /**
+     * Initializes the Preference based on the state of any policies that may affect it,
+     * e.g. by showing a managed icon or disabling clicks on the preference.
+     *
+     * This should be called once, before the preference is displayed.
+     *
+     * @param delegate The delegate that controls whether the preference is managed. May be null,
+     *         then this method does nothing.
+     * @param preference The Preference that is being initialized
+     */
+    public static void initPreference(
+            @Nullable ManagedPreferenceDelegate delegate, Preference preference) {
+        if (delegate == null) return;
+
+        if (delegate.isPreferenceControlledByPolicy(preference)) {
+            preference.setIcon(getManagedByEnterpriseIconId());
+        } else if (delegate.isPreferenceControlledByCustodian(preference)) {
+            preference.setIcon(R.drawable.ic_account_child_grey600_36dp);
+        }
+
+        if (delegate.isPreferenceClickDisabledByPolicy(preference)) {
+            // Disable the views and prevent the Preference from mucking with the enabled state.
+            preference.setShouldDisableView(false);
+
+            // Prevent default click behavior.
+            preference.setFragment(null);
+            preference.setIntent(null);
+            preference.setOnPreferenceClickListener(null);
+        }
+    }
+
+    /**
+     * Disables the Preference's views if the preference is not clickable.
+     *
+     * Note: this disables the View instead of disabling the Preference, so that the Preference
+     * still receives click events, which will trigger a "Managed by your administrator" toast.
+     *
+     * This should be called from the Preference's onBindView() method.
+     *
+     * @param delegate The delegate that controls whether the preference is managed. May be null,
+     *         then this method does nothing.
+     * @param preference The Preference that owns the view
+     * @param view The View that was bound to the Preference
+     */
+    public static void onBindViewToPreference(
+            @Nullable ManagedPreferenceDelegate delegate, Preference preference, View view) {
+        if (delegate != null && delegate.isPreferenceClickDisabledByPolicy(preference)) {
+            ViewUtils.setEnabledRecursive(view, false);
+        }
+    }
+
+    /**
+     * Intercepts the click event if the given Preference is managed and shows a toast in that case.
+     *
+     * This should be called from the Preference's onClick() method.
+     *
+     * @param delegate The delegate that controls whether the preference is managed. May be null,
+     *         then this method does nothing and returns false.
+     * @param preference The Preference that was clicked.
+     * @return true if the click event was handled by this helper and shouldn't be further
+     *         propagated; false otherwise.
+     */
+    public static boolean onClickPreference(
+            @Nullable ManagedPreferenceDelegate delegate, Preference preference) {
+        if (delegate == null || !delegate.isPreferenceClickDisabledByPolicy(preference)) {
+            return false;
+        }
+
+        if (delegate.isPreferenceControlledByPolicy(preference)) {
+            showManagedByAdministratorToast(preference.getContext());
+        } else if (delegate.isPreferenceControlledByCustodian(preference)) {
+            showManagedByParentToast(preference.getContext());
+        } else {
+            // If the preference is disabled, it should be either because it's managed by enterprise
+            // policy or by the custodian.
+            assert false;
+        }
+        return true;
+    }
 }