Fix flickering in the project pane.

This isn't a nice fix but the least evil version of a hack i could come
up. The source of the flickering is: We have a deeply nested structure
of widgets on the project pane. If we call hide() on such a deeply
nested widget, it will activate() it's parent layout synchronously.
That will then post an event (via updateGeometries() ) to its parent
layout that it needs relayouting. Which then will post to its parent
layout the same. And for each LayoutRequested, there's a painting in
between. The fix instead calls activate() up the chain until we are at
the viewport. This immediately relayouts everything. This adds a non
obvoius potentially for breakeage if the widgets are embedded in a
different widget hierarchy. But well, that's life.

src/plugins/projectexplorer/buildstep.cpp

@@ -31,6 +31,7 @@
 #include "buildconfiguration.h"
 
 #include <utils/qtcassert.h>
+#include <QtGui/QLayout>
 
 using namespace ProjectExplorer;
 using namespace ProjectExplorer::Internal;
@@ -133,6 +134,13 @@ bool BuildStep::immutable() const
     return false;
 }
 
+void BuildConfigWidget::fixupLayout(QWidget *widget)
+{
+    QWidget *parent = widget;
+    while((parent = parent->parentWidget()) && parent && parent->layout())
+        parent->layout()->activate();
+}
+
 IBuildStepFactory::IBuildStepFactory()
 {
 

src/plugins/projectexplorer/buildstep.h

@@ -171,6 +171,9 @@ public:
         :QWidget(0)
         {}
 
+    // This function iterates all parents and relayouts
+    // This is a hack to work around flickering
+    void fixupLayout(QWidget *widget);
     virtual QString displayName() const = 0;
 
     // This is called to set up the config widget before showing it

src/plugins/projectexplorer/buildstepspage.cpp

@@ -97,10 +97,14 @@ BuildStepsPage::~BuildStepsPage()
 void BuildStepsPage::toggleDetails()
 {
     QToolButton *tb = qobject_cast<QToolButton *>(sender());
-    if (tb)
+    if (tb) {
-        foreach(const BuildStepsWidgetStruct &s, m_buildSteps)
+        foreach(const BuildStepsWidgetStruct &s, m_buildSteps) {
-            if (s.detailsButton == tb)
+            if (s.detailsButton == tb) {
                 s.widget->setVisible(!s.widget->isVisible());
+                fixupLayout(s.widget);
+            }
+        }
+    }
 }
 
 void BuildStepsPage::updateSummary()

src/plugins/projectexplorer/environmenteditmodel.cpp

@@ -520,9 +520,25 @@ EnvironmentWidget::~EnvironmentWidget()
     m_model = 0;
 }
 
+bool EnvironmentWidget::detailsVisible() const
+{
+    return m_details->isVisible();
+}
+
+void EnvironmentWidget::setDetailsVisible(bool b)
+{
+    m_details->setVisible(b);
+}
+
 void EnvironmentWidget::toggleDetails()
 {
     m_details->setVisible(!m_details->isVisible());
+    emit detailsVisibleChanged(m_details->isVisible());
+}
+
+QWidget *EnvironmentWidget::detailsWidget() const
+{
+    return m_details;
 }
 
 void EnvironmentWidget::setBaseEnvironment(const ProjectExplorer::Environment &env)

src/plugins/projectexplorer/environmenteditmodel.h

@@ -104,12 +104,18 @@ public:
     QList<EnvironmentItem> userChanges() const;
     void setUserChanges(QList<EnvironmentItem> list);
 
+    bool detailsVisible() const;
+    void setDetailsVisible(bool b);
+
+    QWidget *detailsWidget() const;
+
 public slots:
     void updateButtons();
     void toggleDetails();
 
 signals:
     void userChangesUpdated();
+    void detailsVisibleChanged(bool visible);
 
 private slots:
     void editEnvironmentButtonClicked();

src/plugins/projectexplorer/projectwindow.cpp

@@ -76,8 +76,9 @@ PanelsWidget::PanelsWidget(QWidget *parent)
     topwidgetLayout->addWidget(verticalWidget);
     topwidgetLayout->addStretch(10);
 
-    setWidgetResizable(true);
     setFrameStyle(QFrame::NoFrame);
+    setWidgetResizable(true);
+
     setWidget(topwidget);
 }
 

src/plugins/qt4projectmanager/qt4buildenvironmentwidget.cpp

@@ -54,10 +54,18 @@ Qt4BuildEnvironmentWidget::Qt4BuildEnvironmentWidget(Qt4Project *project)
     connect(m_buildEnvironmentWidget, SIGNAL(userChangesUpdated()),
             this, SLOT(environmentModelUserChangesUpdated()));
 
+    connect(m_buildEnvironmentWidget, SIGNAL(detailsVisibleChanged(bool)),
+            this, SLOT(layoutFixup()));
+
     connect(m_clearSystemEnvironmentCheckBox, SIGNAL(toggled(bool)),
             this, SLOT(clearSystemEnvironmentCheckBoxClicked(bool)));
 }
 
+void Qt4BuildEnvironmentWidget::layoutFixup()
+{
+    fixupLayout(m_buildEnvironmentWidget->detailsWidget());
+}
+
 QString Qt4BuildEnvironmentWidget::displayName() const
 {
     return tr("Build Environment");

src/plugins/qt4projectmanager/qt4buildenvironmentwidget.h

@@ -58,6 +58,7 @@ public:
 private slots:
     void environmentModelUserChangesUpdated();
     void clearSystemEnvironmentCheckBoxClicked(bool checked);
+    void layoutFixup();
 
 private:
     ProjectExplorer::EnvironmentWidget *m_buildEnvironmentWidget;

src/plugins/qt4projectmanager/qt4projectconfigwidget.cpp

@@ -120,6 +120,7 @@ Qt4ProjectConfigWidget::~Qt4ProjectConfigWidget()
 void Qt4ProjectConfigWidget::toggleDetails()
 {
     m_ui->detailsWidget->setVisible(!m_ui->detailsWidget->isVisible());
+    fixupLayout(m_ui->detailsWidget);
 }
 
 void Qt4ProjectConfigWidget::updateDetails()