Qt: Check for a sane window geometry.

On Windows (and probably X11) it's possible to set an offscreen window
geometry. Add a rect_on_screen function to qt_ui_utils and use it as a
sanity check in MainWindow::loadWindowGeometry.

If this doesn't work well (e.g. if we end up with dueling Qt and GTK+
geometries) we might want to create separate Qt and GTK+ preferences.

Bug: 11568
Change-Id: Icde1181671770356e87f07d584894ec3148e1bd2
Reviewed-on: https://code.wireshark.org/review/11584
Petri-Dish: Gerald Combs <gerald@wireshark.org>
Tested-by: Petri Dish Buildbot <buildbot-no-reply@wireshark.org>
Reviewed-by: Gerald Combs <gerald@wireshark.org>

3 files changed, 33 insertions, 5 deletions

diff --git a/ui/qt/main_window.cpp b/ui/qt/main_window.cpp
index 00e293e1aa..f28ef8b6f2 100644
--- a/ui/qt/main_window.cpp
+++ b/ui/qt/main_window.cpp
@@ -775,7 +775,7 @@ void MainWindow::dropEvent(QDropEvent *event)
 // position and size preference are enabled.
 void MainWindow::loadWindowGeometry()
 {
-    int min_sensible_dimension_ = 200;
+    int min_sensible_dimension = 200;
 
 #ifndef Q_OS_MAC
     if (recent.gui_geometry_main_maximized) {
@@ -783,14 +783,21 @@ void MainWindow::loadWindowGeometry()
     } else
 #endif
     {
+        QRect recent_geom(recent.gui_geometry_main_x, recent.gui_geometry_main_y,
+                          recent.gui_geometry_main_width, recent.gui_geometry_main_height);
+        if (!rect_on_screen(recent_geom)) {
+            // We're not visible on any screens. Give up and use the default geometry.
+            return;
+        }
+
 //        if (prefs.gui_geometry_save_position) {
-            move(recent.gui_geometry_main_x, recent.gui_geometry_main_y);
+            move(recent_geom.topLeft());
 //        }
 
         if (// prefs.gui_geometry_save_size &&
-                recent.gui_geometry_main_width > min_sensible_dimension_ &&
-                recent.gui_geometry_main_height > min_sensible_dimension_) {
-            resize(recent.gui_geometry_main_width, recent.gui_geometry_main_height);
+                recent_geom.width() > min_sensible_dimension &&
+                recent_geom.height() > min_sensible_dimension) {
+            resize(recent_geom.size());
         }
     }
 }
diff --git a/ui/qt/qt_ui_utils.cpp b/ui/qt/qt_ui_utils.cpp
index aee727ab8b..67bf510b0e 100644
--- a/ui/qt/qt_ui_utils.cpp
+++ b/ui/qt/qt_ui_utils.cpp
@@ -41,7 +41,9 @@
 #include <QDir>
 #include <QFileInfo>
 #include <QFontDatabase>
+#include <QGuiApplication>
 #include <QProcess>
+#include <QScreen>
 #include <QUrl>
 #include <QUuid>
 
@@ -231,6 +233,16 @@ void desktop_show_in_folder(const QString file_path)
     }
 }
 
+bool rect_on_screen(const QRect &rect)
+{
+    foreach (const QScreen *screen, QGuiApplication::screens()) {
+        if (screen->availableGeometry().contains(rect))
+            return true;
+    }
+
+    return false;
+}
+
 /*
  * Editor modelines
  *
diff --git a/ui/qt/qt_ui_utils.h b/ui/qt/qt_ui_utils.h
index 401ddbe00f..1beab1d8fa 100644
--- a/ui/qt/qt_ui_utils.h
+++ b/ui/qt/qt_ui_utils.h
@@ -37,6 +37,7 @@
 
 class QAction;
 class QFont;
+class QRect;
 
 #ifdef __cplusplus
 extern "C" {
@@ -193,6 +194,14 @@ bool qStringCaseLessThan(const QString &s1, const QString &s2);
  */
 void desktop_show_in_folder(const QString file_path);
 
+/**
+ * Test to see if a rect is visible on screen.
+ *
+ * @param rect
+ * @return true if the rect is completely enclosed by one of the display
+ * screens, false otherwise.
+ */
+bool rect_on_screen(const QRect &rect);
 #endif /* __QT_UI_UTILS__H__ */
 
 // XXX Add a routine to fetch the HWND corresponding to a widget using QPlatformIntegration