fix(filemanager): prevent properties dialog flicker

dialogs/filepropertiesdialog.cpp

@@ -100,10 +100,6 @@ QString FilePropertiesDialog::accessedTime() const
 
 void FilePropertiesDialog::init()
 {
-    rootContext()->setContextProperty("main", this);
-
-    load(QUrl("qrc:/qml/Dialogs/PropertiesDialog.qml"));
-
     m_multiple = m_items.count() > 1;
 
     QList<QUrl> list;
@@ -111,12 +107,6 @@ void FilePropertiesDialog::init()
         list.append(item.url());
     }
 
-    m_sizeJob = std::shared_ptr<CFileSizeJob>(new CFileSizeJob);
-    m_sizeJob->start(list);
-
-    connect(m_sizeJob.get(), &CFileSizeJob::sizeChanged, this, &FilePropertiesDialog::updateTotalSize);
-    connect(m_sizeJob.get(), &CFileSizeJob::result, this, &FilePropertiesDialog::updateTotalSize);
-
     if (!m_multiple) {
         KFileItem item = m_items.first();
         QFileInfo info(item.url().toLocalFile());
@@ -154,6 +144,17 @@ void FilePropertiesDialog::init()
         emit locationChanged();
         emit iconNameChanged();
     }
+
+    // Populate the properties before loading the QML window. Its size is
+    // derived from the content, so changing these values after load can
+    // resize the window during its first expose.
+    rootContext()->setContextProperty("main", this);
+    load(QUrl("qrc:/qml/Dialogs/PropertiesDialog.qml"));
+
+    m_sizeJob = std::shared_ptr<CFileSizeJob>(new CFileSizeJob);
+    connect(m_sizeJob.get(), &CFileSizeJob::sizeChanged, this, &FilePropertiesDialog::updateTotalSize);
+    connect(m_sizeJob.get(), &CFileSizeJob::result, this, &FilePropertiesDialog::updateTotalSize);
+    m_sizeJob->start(list);
 }
 
 void FilePropertiesDialog::updateTotalSize()

dialogs/filepropertiesdialog.h

@@ -91,7 +91,7 @@ private:
 
     std::shared_ptr<CFileSizeJob> m_sizeJob;
 
-    bool m_multiple;
+    bool m_multiple = false;
 };
 
 #endif // FILEPROPERTIESDIALOG_H

qml/Dialogs/PropertiesDialog.qml

@@ -64,6 +64,11 @@ FishUI.Window {
                 Layout.preferredWidth: 48
                 Layout.preferredHeight: 48
                 source: main.iconName
+
+                // The source is available while the item is being created.
+                // Refresh after completion so IconItem can load it once its
+                // component lifecycle is ready.
+                Component.onCompleted: updateIcon()
             }
 
             Label {

window.cpp

@@ -21,8 +21,10 @@
 #include "qmltypes.h"
 #include <QEvent>
 #include <QDebug>
+#include <QPointer>
 #include <QQuickWindow>
 #include <QPixmapCache>
+#include <QTimer>
 
 Window::Window(QObject *parent)
     : QQmlApplicationEngine(parent)
@@ -48,9 +50,19 @@ void Window::load(const QUrl &url)
 void Window::show()
 {
     if (QQuickWindow *w = quickWindow()) {
-        w->show();
-        w->raise();
-        w->requestActivate();
+        QPointer<QQuickWindow> window(w);
+
+        // Let QML finish its initial layout pass before the native window is
+        // exposed. Showing it in the same call stack can expose the initial
+        // size for one frame and then resize it, which appears as a flash.
+        QTimer::singleShot(0, w, [window] {
+            if (!window)
+                return;
+
+            window->show();
+            window->raise();
+            window->requestActivate();
+        });
     }
 }