Add an optional flag to QgsTask to indicate that the task can be canc…

…eled without any user facing prompts Useful for non-essential tasks (cherry picked from commit c0f0a49)
qgis · Apr 20, 2020 · 468f481 · 468f481
1 parent d372a8d
commit 468f481
Show file tree

Hide file tree

Showing 3 changed files with 20 additions and 7 deletions.
diff --git a/python/core/auto_generated/qgstaskmanager.sip.in b/python/core/auto_generated/qgstaskmanager.sip.in
@@ -47,6 +47,7 @@ clean up and terminate at the earliest possible convenience.
     enum Flag
     {
       CanCancel,
+      CancelWithoutPrompt,
       AllFlags,
     };
     typedef QFlags<QgsTask::Flag> Flags;

diff --git a/src/app/qgisapp.cpp b/src/app/qgisapp.cpp
@@ -5655,20 +5655,31 @@ void QgisApp::fileExit()
   if ( QgsApplication::taskManager()->countActiveTasks() > 0 )
   {
     QStringList tasks;
-    const auto constActiveTasks = QgsApplication::taskManager()->activeTasks();
-    for ( QgsTask *task : constActiveTasks )
+    const QList< QgsTask * > activeTasks = QgsApplication::taskManager()->activeTasks();
+    for ( QgsTask *task : activeTasks )
     {
+      if ( task->flags() & QgsTask::CancelWithoutPrompt )
+        continue;
+
       tasks << tr( " • %1" ).arg( task->description() );
     }
 
-    // active tasks
-    if ( QMessageBox::question( this, tr( "Active Tasks" ),
-                                tr( "The following tasks are currently running in the background:\n\n%1\n\nDo you want to try canceling these active tasks?" ).arg( tasks.join( QStringLiteral( "\n" ) ) ),
-                                QMessageBox::Yes | QMessageBox::No ) == QMessageBox::Yes )
+    // prompt if any tasks which require user confirmation remain, otherwise just cancel them directly and continue with shutdown.
+    if ( tasks.empty() )
     {
+      // all tasks can be silently terminated without warning
       QgsApplication::taskManager()->cancelAll();
     }
-    return;
+    else
+    {
+      if ( QMessageBox::question( this, tr( "Active Tasks" ),
+                                  tr( "The following tasks are currently running in the background:\n\n%1\n\nDo you want to try canceling these active tasks?" ).arg( tasks.join( QStringLiteral( "\n" ) ) ),
+                                  QMessageBox::Yes | QMessageBox::No ) == QMessageBox::Yes )
+      {
+        QgsApplication::taskManager()->cancelAll();
+      }
+      return;
+    }
   }
 
   QgsCanvasRefreshBlocker refreshBlocker;

diff --git a/src/core/qgstaskmanager.h b/src/core/qgstaskmanager.h
@@ -70,6 +70,7 @@ class CORE_EXPORT QgsTask : public QObject
     enum Flag
     {
       CanCancel = 1 << 1, //!< Task can be canceled
+      CancelWithoutPrompt = 1 << 2, //!< Task can be canceled without any users prompts, e.g. when closing a project or QGIS.
       AllFlags = CanCancel, //!< Task supports all flags
     };
     Q_DECLARE_FLAGS( Flags, Flag )