Merge pull request #1572 from ispyisail/fix/selection-panel-collapse

Shrink the Selection properties panel again when nothing is selected

sources/PropertiesEditor/propertieseditordockwidget.cpp

@@ -19,6 +19,9 @@
 #include "ui_propertieseditordockwidget.h"
 #include "propertieseditorwidget.h"
 
+#include <QMainWindow>
+#include <QTimer>
+
 /**
 	@brief PropertiesEditorDockWidget::PropertiesEditorDockWidget
 	Constructor
@@ -48,6 +51,9 @@ PropertiesEditorDockWidget::~PropertiesEditorDockWidget()
 */
 void PropertiesEditorDockWidget::clear()
 {
+	if (!m_editor_list.isEmpty())
+		rememberHeight();
+
 	foreach (PropertiesEditorWidget *editor, m_editor_list)
 	{
 		m_editor_list.removeOne(editor);
@@ -94,8 +100,11 @@ bool PropertiesEditorDockWidget::addEditor(PropertiesEditorWidget *editor,
 	if (!editor) return false;
 	if (m_editor_list.contains(editor)) return true;
 
+	const bool was_empty = m_editor_list.isEmpty();
 	ui -> m_main_vlayout -> insertWidget(index, editor);
 	m_editor_list << editor;
+	if (was_empty)
+		restoreHeight();
 	return true;
 }
 
@@ -118,9 +127,84 @@ QList<PropertiesEditorWidget *> PropertiesEditorDockWidget::editors() const
 */
 bool PropertiesEditorDockWidget::removeEditor(PropertiesEditorWidget *editor)
 {
+	if (m_editor_list.size() == 1 && m_editor_list.first() == editor)
+		rememberHeight();
+
 	bool result = m_editor_list.removeOne(editor);
 	if (result)
 		ui -> m_main_vlayout -> removeWidget(editor);
 
 	return result;
 }
+
+/**
+	@brief PropertiesEditorDockWidget::rememberHeight
+	The dock shrinks to its title bar while it has no editor, and the
+	other docks of its area take the room. Keep the heights the docks
+	of the area have now, the heights the user gave them, to give them
+	back when an editor comes back.
+*/
+void PropertiesEditorDockWidget::rememberHeight()
+{
+		// Still the shrunk height: the last editor came and went
+		// before the heights were given back
+	if (m_restore_pending || isFloating() || !isVisible())
+		return;
+	auto main_window = qobject_cast<QMainWindow *>(parentWidget());
+	if (!main_window)
+		return;
+
+	m_area_docks.clear();
+	m_area_heights.clear();
+	const Qt::DockWidgetArea area = main_window->dockWidgetArea(this);
+	for (QDockWidget *dock : main_window->findChildren<QDockWidget *>())
+	{
+		if (dock->parentWidget() == main_window && !dock->isFloating()
+			&& dock->isVisible()
+			&& main_window->dockWidgetArea(dock) == area)
+		{
+			m_area_docks << dock;
+			m_area_heights << dock->height();
+		}
+	}
+}
+
+/**
+	@brief PropertiesEditorDockWidget::restoreHeight
+	Give the docks of the area back the heights they had before this
+	dock shrank. Without this the area is split again from the docks'
+	size hints, and giving this dock alone its height back takes the
+	room only from its neighbours.
+*/
+void PropertiesEditorDockWidget::restoreHeight()
+{
+	if (m_area_docks.isEmpty() || m_restore_pending)
+		return;
+
+	m_restore_pending = true;
+		// Once the layout has given the dock its maximum height back
+	QTimer::singleShot(0, this, [this]() {
+		m_restore_pending = false;
+		auto main_window = qobject_cast<QMainWindow *>(parentWidget());
+		if (!main_window || isFloating() || !isVisible()
+			|| m_editor_list.isEmpty())
+			return;
+
+		QList<QDockWidget *> docks;
+		QList<int> heights;
+		const Qt::DockWidgetArea area = main_window->dockWidgetArea(this);
+		for (int i = 0 ; i < m_area_docks.size() ; ++i)
+		{
+			QDockWidget *dock = m_area_docks.at(i);
+				// Closed, moved or deleted since
+			if (dock && !dock->isFloating() && dock->isVisible()
+				&& main_window->dockWidgetArea(dock) == area)
+			{
+				docks << dock;
+				heights << m_area_heights.at(i);
+			}
+		}
+		if (docks.contains(this))
+			main_window->resizeDocks(docks, heights, Qt::Vertical);
+	});
+}

sources/PropertiesEditor/propertieseditordockwidget.h

@@ -19,6 +19,7 @@
 #define SELECTIONPROPERTIESDOCKWIDGET_H
 
 #include <QDockWidget>
+#include <QPointer>
 
 class PropertiesEditorWidget;
 
@@ -45,7 +46,13 @@ class PropertiesEditorDockWidget : public QDockWidget
 		QList <PropertiesEditorWidget *> m_editor_list;
 
 	private:
+		void rememberHeight();
+		void restoreHeight();
+
 		Ui::PropertiesEditorDockWidget *ui;
+		QList<QPointer<QDockWidget>> m_area_docks;
+		QList<int> m_area_heights;
+		bool m_restore_pending = false;
 };
 
 #endif // SELECTIONPROPERTIESDOCKWIDGET_H

sources/PropertiesEditor/propertieseditordockwidget.ui

@@ -16,7 +16,7 @@
   <widget class="QWidget" name="dockWidgetContents">
    <layout class="QVBoxLayout" name="verticalLayout">
     <property name="sizeConstraint">
-     <enum>QLayout::SetDefaultConstraint</enum>
+     <enum>QLayout::SetMaximumSize</enum>
     </property>
     <property name="leftMargin">
      <number>0</number>

tests/qttest/CMakeLists.txt

@@ -308,8 +308,8 @@ qet_add_app_test(tst_imagehandleescape tst_imagehandleescape.cpp)
 # pixels and position; an <image> with no picture does not stop the others.
 qet_add_app_test(tst_folioimageload tst_folioimageload.cpp)
 
-# The Selection properties panel keeps the height the user gave it when the
-# selection has nothing to edit for a moment (#1439).
+# The Selection properties panel shrinks while the selection has nothing to
+# edit (#1566) and gets back the height the user gave it (#1439).
 qet_add_app_test(tst_selectionpanelheight tst_selectionpanelheight.cpp)
 
 # Opening a project before the elements panel's first reload() left its tree

tests/qttest/tst_selectionpanelheight.cpp

@@ -6,10 +6,11 @@
 
 #include <QDockWidget>
 
-// The Selection properties panel keeps the height the user gave it when the
-// selection has nothing it can edit for a moment (#1439). It used to shrink
-// to its title bar, the other panels took the room, and an element selected
-// again brought the panel back at its default height.
+// The Selection properties panel shrinks to its title bar while the selection
+// has nothing it can edit, so the other panels get the room (#1566), and gets
+// back the height the user gave it when an element is selected again. Before
+// #1439 it came back at its default height; #1533 kept the height but no
+// longer shrank.
 class tst_selectionpanelheight : public QObject
 {
 	Q_OBJECT
@@ -57,10 +58,12 @@ class tst_selectionpanelheight : public QObject
 			const int user = panel->height();
 			QVERIFY2(user > start, "the panel could not be made taller");
 
-			select(nullptr);
-			QCOMPARE(panel->height(), user);
-			select(element);
-			QCOMPARE(panel->height(), user);
+			for (int round = 0; round < 2; ++round) {
+				select(nullptr);
+				QVERIFY2(panel->height() < start / 4, "the empty panel did not shrink");
+				select(element);
+				QCOMPARE(panel->height(), user);
+			}
 		}
 };