Factor an overlay widget out of progress indicator

The principle of having a widget on top of all other children of the
same parent, for the purpose of painting an overlay, is generic.

Change-Id: I6d3ee89cc51354988fedcc40340bb45a065db607
Reviewed-by: David Schulz <david.schulz@qt.io>

src/libs/utils/CMakeLists.txt

@@ -96,6 +96,7 @@ add_qtc_library(Utils
     osspecificaspects.h
     outputformat.h
     outputformatter.cpp outputformatter.h
+    overlaywidget.cpp overlaywidget.h
     overridecursor.cpp overridecursor.h
     parameteraction.cpp parameteraction.h
     pathchooser.cpp pathchooser.h

src/libs/utils/overlaywidget.cpp

@@ -0,0 +1,76 @@
+/****************************************************************************
+**
+** Copyright (C) 2020 The Qt Company Ltd.
+** Contact: https://www.qt.io/licensing/
+**
+** This file is part of Qt Creator.
+**
+** Commercial License Usage
+** Licensees holding valid commercial Qt licenses may use this file in
+** accordance with the commercial license agreement provided with the
+** Software or, alternatively, in accordance with the terms contained in
+** a written agreement between you and The Qt Company. For licensing terms
+** and conditions see https://www.qt.io/terms-conditions. For further
+** information use the contact form at https://www.qt.io/contact-us.
+**
+** GNU General Public License Usage
+** Alternatively, this file may be used under the terms of the GNU
+** General Public License version 3 as published by the Free Software
+** Foundation with exceptions as appearing in the file LICENSE.GPL3-EXCEPT
+** included in the packaging of this file. Please review the following
+** information to ensure the GNU General Public License requirements will
+** be met: https://www.gnu.org/licenses/gpl-3.0.html.
+**
+****************************************************************************/
+
+#include "overlaywidget.h"
+
+#include "qtcassert.h"
+
+#include <QEvent>
+#include <QPainter>
+
+Utils::OverlayWidget::OverlayWidget(QWidget *parent)
+{
+    setAttribute(Qt::WA_TransparentForMouseEvents);
+    if (parent)
+        attachToWidget(parent);
+}
+
+void Utils::OverlayWidget::setPaintFunction(const Utils::OverlayWidget::PaintFunction &paint)
+{
+    m_paint = paint;
+}
+
+bool Utils::OverlayWidget::eventFilter(QObject *obj, QEvent *ev)
+{
+    if (obj == parent() && ev->type() == QEvent::Resize)
+        resizeToParent();
+    return QWidget::eventFilter(obj, ev);
+}
+
+void Utils::OverlayWidget::paintEvent(QPaintEvent *ev)
+{
+    if (m_paint) {
+        QPainter p(this);
+        m_paint(this, p, ev);
+    }
+}
+
+void Utils::OverlayWidget::attachToWidget(QWidget *parent)
+{
+    if (parentWidget())
+        parentWidget()->removeEventFilter(this);
+    setParent(parent);
+    if (parent) {
+        parent->installEventFilter(this);
+        resizeToParent();
+        raise();
+    }
+}
+
+void Utils::OverlayWidget::resizeToParent()
+{
+    QTC_ASSERT(parentWidget(), return );
+    setGeometry(QRect(QPoint(0, 0), parentWidget()->size()));
+}

src/libs/utils/overlaywidget.h

@@ -0,0 +1,55 @@
+/****************************************************************************
+**
+** Copyright (C) 2020 The Qt Company Ltd.
+** Contact: https://www.qt.io/licensing/
+**
+** This file is part of Qt Creator.
+**
+** Commercial License Usage
+** Licensees holding valid commercial Qt licenses may use this file in
+** accordance with the commercial license agreement provided with the
+** Software or, alternatively, in accordance with the terms contained in
+** a written agreement between you and The Qt Company. For licensing terms
+** and conditions see https://www.qt.io/terms-conditions. For further
+** information use the contact form at https://www.qt.io/contact-us.
+**
+** GNU General Public License Usage
+** Alternatively, this file may be used under the terms of the GNU
+** General Public License version 3 as published by the Free Software
+** Foundation with exceptions as appearing in the file LICENSE.GPL3-EXCEPT
+** included in the packaging of this file. Please review the following
+** information to ensure the GNU General Public License requirements will
+** be met: https://www.gnu.org/licenses/gpl-3.0.html.
+**
+****************************************************************************/
+
+#pragma once
+
+#include "utils_global.h"
+
+#include <QWidget>
+
+namespace Utils {
+
+class QTCREATOR_UTILS_EXPORT OverlayWidget : public QWidget
+{
+    Q_OBJECT
+public:
+    using PaintFunction = std::function<void(QWidget *, QPainter &, QPaintEvent *)>;
+
+    explicit OverlayWidget(QWidget *parent = nullptr);
+
+    void attachToWidget(QWidget *parent);
+    void setPaintFunction(const PaintFunction &paint);
+
+protected:
+    bool eventFilter(QObject *obj, QEvent *ev) override;
+    void paintEvent(QPaintEvent *ev) override;
+
+private:
+    void resizeToParent();
+
+    PaintFunction m_paint;
+};
+
+} // namespace Utils

src/libs/utils/progressindicator.cpp

@@ -220,9 +220,11 @@ void ProgressIndicatorPainter::nextAnimationStep()
     \sa setIndicatorSize
 */
 ProgressIndicator::ProgressIndicator(ProgressIndicatorSize size, QWidget *parent)
-    : QWidget(parent), m_paint(size)
+    : OverlayWidget(parent)
+    , m_paint(size)
 {
-    setAttribute(Qt::WA_TransparentForMouseEvents);
+    setPaintFunction(
+        [this](QWidget *w, QPainter &p, QPaintEvent *) { m_paint.paint(p, w->rect()); });
     m_paint.setUpdateCallback([this]() { update(); });
     updateGeometry();
 }
@@ -248,29 +250,6 @@ QSize ProgressIndicator::sizeHint() const
     return m_paint.size();
 }
 
-/*!
-    Makes the indicator a child of \a parent, automatically centering on it,
-    and adapting to size changes.
-*/
-void ProgressIndicator::attachToWidget(QWidget *parent)
-{
-    if (parentWidget())
-        parentWidget()->removeEventFilter(this);
-    setParent(parent);
-    parent->installEventFilter(this);
-    resizeToParent();
-    raise();
-}
-
-/*!
-    \internal
-*/
-void ProgressIndicator::paintEvent(QPaintEvent *)
-{
-    QPainter p(this);
-    m_paint.paint(p, rect());
-}
-
 /*!
     \internal
 */
@@ -287,24 +266,4 @@ void ProgressIndicator::hideEvent(QHideEvent *)
     m_paint.stopAnimation();
 }
 
-/*!
-    \internal
-*/
-bool ProgressIndicator::eventFilter(QObject *obj, QEvent *ev)
-{
-    if (obj == parent() && ev->type() == QEvent::Resize) {
-        resizeToParent();
-    }
-    return QWidget::eventFilter(obj, ev);
-}
-
-/*!
-    \internal
-*/
-void ProgressIndicator::resizeToParent()
-{
-    QTC_ASSERT(parentWidget(), return);
-    setGeometry(QRect(QPoint(0, 0), parentWidget()->size()));
-}
-
 } // namespace Utils

src/libs/utils/progressindicator.h

@@ -25,6 +25,7 @@
 
 #pragma once
 
+#include "overlaywidget.h"
 #include "utils_global.h"
 
 #include <QTimer>
@@ -76,7 +77,7 @@ private:
     UpdateCallback m_callback;
 };
 
-class QTCREATOR_UTILS_EXPORT ProgressIndicator : public QWidget
+class QTCREATOR_UTILS_EXPORT ProgressIndicator : public OverlayWidget
 {
     Q_OBJECT
 public:
@@ -86,17 +87,11 @@ public:
 
     QSize sizeHint() const final;
 
-    void attachToWidget(QWidget *parent);
-
 protected:
-    void paintEvent(QPaintEvent *) final;
     void showEvent(QShowEvent *) final;
     void hideEvent(QHideEvent *) final;
-    bool eventFilter(QObject *obj, QEvent *ev) final;
 
 private:
-    void resizeToParent();
-
     ProgressIndicatorPainter m_paint;
 };
 

src/libs/utils/utils-lib.pri

@@ -132,7 +132,8 @@ SOURCES += \
     $$PWD/jsontreeitem.cpp \
     $$PWD/namevaluevalidator.cpp \
     $$PWD/camelcasecursor.cpp \
-    $$PWD/infolabel.cpp
+    $$PWD/infolabel.cpp \
+    $$PWD/overlaywidget.cpp
 
 HEADERS += \
     $$PWD/environmentfwd.h \
@@ -279,7 +280,8 @@ HEADERS += \
     $$PWD/listmodel.h \
     $$PWD/namevaluevalidator.h \
     $$PWD/camelcasecursor.h \
-    $$PWD/infolabel.h
+    $$PWD/infolabel.h \
+    $$PWD/overlaywidget.h
 
 FORMS += $$PWD/filewizardpage.ui \
     $$PWD/projectintropage.ui \

src/libs/utils/utils.qbs

@@ -176,6 +176,8 @@ Project {
             "outputformat.h",
             "outputformatter.cpp",
             "outputformatter.h",
+            "overlaywidget.cpp",
+            "overlaywidget.h",
             "overridecursor.cpp",
             "overridecursor.h",
             "parameteraction.cpp",