Notify canGoBack/canGoForward changes based on web actions

Before, QQuickWebEngineView's canGoBack/canGoForward change signals
are based on urlChanged. But the urlChanged signal may be emitted
slightly before the value of canGoBack/canGoForwad actually changes,
resulting in a missed change notification.

After, they get their own signals, which are forwarded from the
QQuickWebEngineAction::enabledChanged signal of the respective web
actions.

Fixes: QTBUG-91565
Change-Id: Id411eb146c776e2824fd2447660e8857974da32e
Reviewed-by: Allan Sandfeld Jensen <allan.jensen@qt.io>

4 files changed, 56 insertions, 3 deletions

diff --git a/src/webengine/api/qquickwebengineview.cpp b/src/webengine/api/qquickwebengineview.cpp
index 1bb89ac68..6ab1c97cb 100644
--- a/src/webengine/api/qquickwebengineview.cpp
+++ b/src/webengine/api/qquickwebengineview.cpp
@@ -876,6 +876,11 @@ QQuickWebEngineView::QQuickWebEngineView(QQuickItem *parent)
     d->q_ptr = this;
     this->setActiveFocusOnTab(true);
     this->setFlags(QQuickItem::ItemIsFocusScope | QQuickItem::ItemAcceptsDrops);
+
+    connect(action(WebAction::Back), &QQuickWebEngineAction::enabledChanged,
+            this, &QQuickWebEngineView::canGoBackChanged);
+    connect(action(WebAction::Forward), &QQuickWebEngineAction::enabledChanged,
+            this, &QQuickWebEngineView::canGoForwardChanged);
 }
 
 QQuickWebEngineView::~QQuickWebEngineView()
diff --git a/src/webengine/api/qquickwebengineview_p.h b/src/webengine/api/qquickwebengineview_p.h
index ab84b2600..3155bce37 100644
--- a/src/webengine/api/qquickwebengineview_p.h
+++ b/src/webengine/api/qquickwebengineview_p.h
@@ -116,8 +116,8 @@ class Q_WEBENGINE_PRIVATE_EXPORT QQuickWebEngineView : public QQuickItem {
     Q_PROPERTY(bool loading READ isLoading NOTIFY loadingChanged FINAL)
     Q_PROPERTY(int loadProgress READ loadProgress NOTIFY loadProgressChanged FINAL)
     Q_PROPERTY(QString title READ title NOTIFY titleChanged FINAL)
-    Q_PROPERTY(bool canGoBack READ canGoBack NOTIFY urlChanged FINAL)
-    Q_PROPERTY(bool canGoForward READ canGoForward NOTIFY urlChanged FINAL)
+    Q_PROPERTY(bool canGoBack READ canGoBack NOTIFY canGoBackChanged FINAL)
+    Q_PROPERTY(bool canGoForward READ canGoForward NOTIFY canGoForwardChanged FINAL)
     Q_PROPERTY(bool isFullScreen READ isFullScreen NOTIFY isFullScreenChanged REVISION 1 FINAL)
     Q_PROPERTY(qreal zoomFactor READ zoomFactor WRITE setZoomFactor NOTIFY zoomFactorChanged REVISION 1 FINAL)
     Q_PROPERTY(QQuickWebEngineProfile *profile READ profile WRITE setProfile NOTIFY profileChanged FINAL REVISION 1)
@@ -581,6 +581,8 @@ Q_SIGNALS:
     Q_REVISION(10) void recommendedStateChanged(LifecycleState state);
     Q_REVISION(10) void findTextFinished(const QWebEngineFindTextResult &result);
     Q_REVISION(11) void renderProcessPidChanged(qint64 pid);
+    Q_REVISION(11) void canGoBackChanged();
+    Q_REVISION(11) void canGoForwardChanged();
 
 #if QT_CONFIG(webengine_testsupport)
     void testSupportChanged();
diff --git a/tests/auto/quick/publicapi/tst_publicapi.cpp b/tests/auto/quick/publicapi/tst_publicapi.cpp
index dad962576..950c7375a 100644
--- a/tests/auto/quick/publicapi/tst_publicapi.cpp
+++ b/tests/auto/quick/publicapi/tst_publicapi.cpp
@@ -687,7 +687,9 @@ static const QStringList expectedAPI = QStringList()
     << "QQuickWebEngineView.backgroundColor --> QColor"
     << "QQuickWebEngineView.backgroundColorChanged() --> void"
     << "QQuickWebEngineView.canGoBack --> bool"
+    << "QQuickWebEngineView.canGoBackChanged() --> void"
     << "QQuickWebEngineView.canGoForward --> bool"
+    << "QQuickWebEngineView.canGoForwardChanged() --> void"
     << "QQuickWebEngineView.certificateError(QQuickWebEngineCertificateError*) --> void"
     << "QQuickWebEngineView.colorDialogRequested(QQuickWebEngineColorDialogRequest*) --> void"
     << "QQuickWebEngineView.contentsSize --> QSizeF"
diff --git a/tests/auto/quick/qmltests/data/tst_navigationHistory.qml b/tests/auto/quick/qmltests/data/tst_navigationHistory.qml
index 6ed232589..f32af2106 100644
--- a/tests/auto/quick/qmltests/data/tst_navigationHistory.qml
+++ b/tests/auto/quick/qmltests/data/tst_navigationHistory.qml
@@ -26,7 +26,8 @@
 **
 ****************************************************************************/
 
-import QtQuick 2.0
+import QtQuick 2.15
+import QtQuick.Controls 2.15
 import QtTest 1.0
 import QtWebEngine 1.2
 
@@ -59,6 +60,20 @@ TestWebEngineView {
             }
     }
 
+    Button {
+        id: backButton
+        text: "Back"
+        enabled: webEngineView.canGoBack
+        onClicked: webEngineView.goBack()
+    }
+
+    Button {
+        id: forwardButton
+        text: "Forward"
+        enabled: webEngineView.canGoForward
+        onClicked: webEngineView.goForward()
+    }
+
     TestCase {
         name: "WebEngineViewNavigationHistory"
 
@@ -142,5 +157,34 @@ TestWebEngineView {
             compare(backItemsList.count, 0)
             compare(forwardItemsList.count, 0)
         }
+
+        function test_navigationButtons() {
+            compare(webEngineView.loadProgress, 0)
+
+            webEngineView.url = Qt.resolvedUrl("test1.html")
+            verify(webEngineView.waitForLoadSucceeded())
+            compare(backButton.enabled, false)
+            compare(forwardButton.enabled, false)
+
+            webEngineView.url = Qt.resolvedUrl("test2.html")
+            verify(webEngineView.waitForLoadSucceeded())
+            compare(backButton.enabled, true)
+            compare(forwardButton.enabled, false)
+
+            webEngineView.url = Qt.resolvedUrl("test3.html")
+            verify(webEngineView.waitForLoadSucceeded())
+            compare(backButton.enabled, true)
+            compare(forwardButton.enabled, false)
+
+            backButton.clicked()
+            verify(webEngineView.waitForLoadSucceeded())
+            compare(backButton.enabled, true)
+            compare(forwardButton.enabled, true)
+
+            webEngineView.url = Qt.resolvedUrl("test1.html")
+            verify(webEngineView.waitForLoadSucceeded())
+            compare(backButton.enabled, true)
+            compare(forwardButton.enabled, false)
+        }
     }
 }