ProjectExplorer: Don't force a smallish maximum panels widget width

This widget can often benefit from more space, as we currently often see
cut-off text etc.
We now use a splitter, with the main widget originally taking up its
current minimum size, and the user being able to enlarge it according to
their preference.

Change-Id: Ibc5f0a54e0659613b3094181db258717d1886cb9
Reviewed-by: hjk <hjk@qt.io>

src/plugins/projectexplorer/panelswidget.cpp

@@ -25,15 +25,18 @@
 
 #include "panelswidget.h"
 
-#include <QPainter>
-#include <QVBoxLayout>
-#include <QLabel>
+#include <coreplugin/minisplitter.h>
 
 #include <utils/stylehelper.h>
 #include <utils/theme/theme.h>
 #include <utils/qtcassert.h>
 #include <utils/styledbar.h>
 
+#include <QLabel>
+#include <QPainter>
+#include <QScrollArea>
+#include <QVBoxLayout>
+
 using namespace Utils;
 
 namespace ProjectExplorer {
@@ -46,53 +49,27 @@ const int ABOVE_CONTENTS_MARGIN = 4;
 const int BELOW_CONTENTS_MARGIN = 16;
 const int PANEL_LEFT_MARGIN = 70;
 
-class RootWidget : public QWidget
-{
-public:
-    RootWidget(QWidget *parent) : QWidget(parent) {
-        setFocusPolicy(Qt::NoFocus);
-    }
-    void paintEvent(QPaintEvent *) override;
-};
-
-void RootWidget::paintEvent(QPaintEvent *e)
-{
-    QWidget::paintEvent(e);
-
-    if (!creatorTheme()->flag(Theme::FlatToolBars)) {
-        // draw separator line to the right of the settings panel
-        QPainter painter(this);
-        QColor light = StyleHelper::mergedColors(
-                    palette().button().color(), Qt::white, 30);
-        QColor dark = StyleHelper::mergedColors(
-                    palette().button().color(), Qt::black, 85);
-
-        painter.setPen(light);
-        painter.drawLine(rect().topRight(), rect().bottomRight());
-        painter.setPen(dark);
-        painter.drawLine(rect().topRight() - QPoint(1,0), rect().bottomRight() - QPoint(1,0));
-    }
-}
 }
 
 ///
 // PanelsWidget
 ///
 
-PanelsWidget::PanelsWidget(QWidget *parent) :
-    QWidget(parent),
-    m_root(new RootWidget(this))
+PanelsWidget::PanelsWidget(QWidget *parent) : QWidget(parent)
 {
-    // We want a 900px wide widget with and the scrollbar at the
-    // side of the screen.
-    m_root->setMaximumWidth(900);
+    const auto splitter = new Core::MiniSplitter(this);
+    m_root = new QWidget(nullptr);
+    m_root->setFocusPolicy(Qt::NoFocus);
     m_root->setContentsMargins(0, 0, 40, 0);
+    splitter->addWidget(m_root);
+    splitter->addWidget(new QWidget);
+    splitter->setStretchFactor(1, 100); // Force root widget to its minimum size initially
 
-    m_scroller = new QScrollArea(this);
-    m_scroller->setWidget(m_root);
-    m_scroller->setFrameStyle(QFrame::NoFrame);
-    m_scroller->setWidgetResizable(true);
-    m_scroller->setFocusPolicy(Qt::NoFocus);
+    const auto scroller = new QScrollArea(this);
+    scroller->setWidget(splitter);
+    scroller->setFrameStyle(QFrame::NoFrame);
+    scroller->setWidgetResizable(true);
+    scroller->setFocusPolicy(Qt::NoFocus);
 
     // The layout holding the individual panels:
     auto topLayout = new QVBoxLayout(m_root);
@@ -110,7 +87,7 @@ PanelsWidget::PanelsWidget(QWidget *parent) :
     layout->setContentsMargins(0, 0, 0, 0);
     layout->setSpacing(0);
     layout->addWidget(new Utils::StyledBar(this));
-    layout->addWidget(m_scroller);
+    layout->addWidget(scroller);
 
     //layout->addWidget(new FindToolBarPlaceHolder(this));
 }

src/plugins/projectexplorer/panelswidget.h

@@ -27,7 +27,7 @@
 
 #include "projectexplorer_export.h"
 
-#include <QScrollArea>
+#include <QWidget>
 
 QT_BEGIN_NAMESPACE
 class QGridLayout;
@@ -51,7 +51,6 @@ public:
 
 private:
     QGridLayout *m_layout;
-    QScrollArea *m_scroller;
     QWidget *m_root;
 };