Bug 1583265 - Add GeckoSession.purgeHistory() r=geckoview-reviewers,snorp,droeh

Differential Revision: https://phabricator.services.mozilla.com/D47137

--HG--
extra : moz-landing-system : lando

mobile/android/geckoview/api.txt

@@ -544,6 +544,7 @@ package org.mozilla.geckoview {
     method @AnyThread public void loadUri(@NonNull Uri, @Nullable Uri, int);
     method @AnyThread public void loadUri(@NonNull Uri, @Nullable Uri, int, @Nullable Map<String,String>);
     method @UiThread public void open(@NonNull GeckoRuntime);
+    method @AnyThread public void purgeHistory();
     method @AnyThread public void readFromParcel(@NonNull Parcel);
     method @UiThread public void releaseDisplay(@NonNull GeckoDisplay);
     method @AnyThread public void reload();

mobile/android/geckoview/src/androidTest/java/org/mozilla/geckoview/test/NavigationDelegateTest.kt

@@ -1335,4 +1335,56 @@ class NavigationDelegateTest : BaseSessionTest() {
             }
         })
     }
+
+    @Test fun purgeHistory() {
+        sessionRule.session.loadUri("$TEST_ENDPOINT$HELLO_HTML_PATH")
+        sessionRule.waitUntilCalled(object : Callbacks.NavigationDelegate {
+            @AssertCalled(count = 1)
+            override fun onCanGoBack(session: GeckoSession, canGoBack: Boolean) {
+                assertThat("Session should not be null", session, notNullValue())
+                assertThat("Cannot go back", canGoBack, equalTo(false))
+            }
+
+            @AssertCalled(count = 1)
+            override fun onCanGoForward(session: GeckoSession, canGoForward: Boolean) {
+                assertThat("Session should not be null", session, notNullValue())
+                assertThat("Cannot go forward", canGoForward, equalTo(false))
+            }
+        })
+        sessionRule.session.loadUri("$TEST_ENDPOINT$HELLO2_HTML_PATH")
+        sessionRule.waitUntilCalled(object : Callbacks.All {
+            @AssertCalled(count = 1)
+            override fun onCanGoBack(session: GeckoSession, canGoBack: Boolean) {
+                assertThat("Session should not be null", session, notNullValue())
+                assertThat("Cannot go back", canGoBack, equalTo(true))
+            }
+            @AssertCalled(count = 1)
+            override fun onCanGoForward(session: GeckoSession, canGoForward: Boolean) {
+                assertThat("Session should not be null", session, notNullValue())
+                assertThat("Cannot go forward", canGoForward, equalTo(false))
+            }
+            @AssertCalled(count = 1)
+            override fun onHistoryStateChange(session: GeckoSession, state: GeckoSession.HistoryDelegate.HistoryList) {
+                assertThat("History should have two entries", state.size, equalTo(2))
+            }
+        })
+        sessionRule.session.purgeHistory()
+        sessionRule.waitUntilCalled(object : Callbacks.All {
+            @AssertCalled(count = 1)
+            override fun onHistoryStateChange(session: GeckoSession, state: GeckoSession.HistoryDelegate.HistoryList) {
+                assertThat("History should have one entry", state.size, equalTo(1))
+            }
+            @AssertCalled(count = 1)
+            override fun onCanGoBack(session: GeckoSession, canGoBack: Boolean) {
+                assertThat("Session should not be null", session, notNullValue())
+                assertThat("Cannot go back", canGoBack, equalTo(false))
+            }
+
+            @AssertCalled(count = 1)
+            override fun onCanGoForward(session: GeckoSession, canGoForward: Boolean) {
+                assertThat("Session should not be null", session, notNullValue())
+                assertThat("Cannot go forward", canGoForward, equalTo(false))
+            }
+        })
+    }
 }

mobile/android/geckoview/src/main/java/org/mozilla/geckoview/GeckoSession.java

@@ -732,11 +732,20 @@ public class GeckoSession implements Parcelable {
                     final HistoryDelegate historyDelegate = getHistoryDelegate();
                     final GeckoBundle update = message.getBundle("data");
                     if (update != null) {
+                        final int previousHistorySize = mStateCache.size();
                         mStateCache.updateSessionState(update);
                         final SessionState state = new SessionState(mStateCache);
                         delegate.onSessionStateChange(GeckoSession.this, state);
-                        if (historyDelegate != null && update.getBundle("historychange") != null) {
-                            historyDelegate.onHistoryStateChange(GeckoSession.this, state);
+                        if (update.getBundle("historychange") != null) {
+                            if (historyDelegate != null) {
+                                historyDelegate.onHistoryStateChange(GeckoSession.this, state);
+                            }
+                            // If the previous history was larger than one entry and the new size is one, it means the
+                            // History has been purged and the navigation delegate needs to be update.
+                            if ((previousHistorySize > 1) && (state.size() == 1) && mNavigationHandler.getDelegate() != null) {
+                                mNavigationHandler.getDelegate().onCanGoForward(GeckoSession.this, false);
+                                mNavigationHandler.getDelegate().onCanGoBack(GeckoSession.this, false);
+                            }
                         }
                     }
                 }
@@ -1898,6 +1907,17 @@ public class GeckoSession implements Parcelable {
         mEventDispatcher.dispatch("GeckoView:GotoHistoryIndex", msg);
     }
 
+    /**
+     * Purge history for the session.
+     * The session history is used for back and forward history.
+     * Purging the session history means {@link NavigationDelegate#onCanGoBack(GeckoSession, boolean)}
+     * and {@link NavigationDelegate#onCanGoForward(GeckoSession, boolean)} will be false.
+     */
+    @AnyThread
+    public void purgeHistory() {
+        mEventDispatcher.dispatch("GeckoView:PurgeHistory", null);
+    }
+
     @Retention(RetentionPolicy.SOURCE)
     @IntDef(flag = true,
             value = {FINDER_FIND_BACKWARDS, FINDER_FIND_LINKS_ONLY,

mobile/android/geckoview/src/main/java/org/mozilla/geckoview/doc-files/CHANGELOG.md

@@ -41,6 +41,8 @@ exclude: true
 - ⚠️ Added [`GeckoView.onTouchEventForResult`][71.15] and modified
   [`PanZoomController.onTouchEvent`][71.16] to return how the touch event was handled. This
   allows apps to know if an event is handled by touch event listeners in web content. The methods in `PanZoomController` now return `int` instead of `boolean`.
+- Added [`GeckoSession.purgeHistory`][71.17] allowing apps to clear a session's history.
+  ([bug 1583265]({{bugzilla}}1583265))
 
 [71.1]: {{javadoc_uri}}/RuntimeTelemetry.Delegate.html#onBooleanScalar-org.mozilla.geckoview.RuntimeTelemetry.Metric-
 [71.2]: {{javadoc_uri}}/RuntimeTelemetry.Delegate.html#onLongScalar-org.mozilla.geckoview.RuntimeTelemetry.Metric-
@@ -57,6 +59,7 @@ exclude: true
 [71.13]: {{javadoc_uri}}/GeckoSession.ContentDelegate.html#onFirstContentfulPaint-org.mozilla.geckoview.GeckoSession-
 [71.15]: {{javadoc_uri}}/GeckoView.html#onTouchEventForResult-android.view.MotionEvent-
 [71.16]: {{javadoc_uri}}/PanZoomController.html#onTouchEvent-android.view.MotionEvent-
+[71.17]: {{javadoc_uri}}/GeckoSession.html#purgeHistory--
 
 ## v70
 - Added API for session context assignment
@@ -379,4 +382,4 @@ exclude: true
 [65.24]: {{javadoc_uri}}/CrashReporter.html#sendCrashReport-android.content.Context-android.os.Bundle-java.lang.String-
 [65.25]: {{javadoc_uri}}/GeckoResult.html
 
-[api-version]: 68710f52723909eea09a02b94b618a527cc9dfc8
+[api-version]: c588ee34768a61847786ba32b4cefdbe60eed774

mobile/android/modules/geckoview/GeckoViewNavigation.jsm

@@ -64,6 +64,7 @@ class GeckoViewNavigation extends GeckoViewModule {
       "GeckoView:LoadUri",
       "GeckoView:Reload",
       "GeckoView:Stop",
+      "GeckoView:PurgeHistory",
     ]);
 
     this.messageManager.addMessageListener("Browser:LoadURI", this);
@@ -243,6 +244,9 @@ class GeckoViewNavigation extends GeckoViewModule {
       case "GeckoView:Stop":
         this.browser.stop();
         break;
+      case "GeckoView:PurgeHistory":
+        this.browser.purgeSessionHistory();
+        break;
     }
   }