Extract a fading indicator widget into utils

That can show either a pixmap, or some text.
Used for the wrap indicator when searching, and for the 'presentation
mode' of action manager.

Change-Id: I4d603fb5750d7539c50de7ef8fd6c8545293d5b9
Reviewed-by: Tobias Hunger <tobias.hunger@theqtcompany.com>

src/libs/utils/fadingindicator.cpp

@@ -0,0 +1,146 @@
+/****************************************************************************
+**
+** Copyright (C) 2015 The Qt Company Ltd.
+** Contact: http://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 http://www.qt.io/terms-conditions.  For further information
+** use the contact form at http://www.qt.io/contact-us.
+**
+** GNU Lesser General Public License Usage
+** Alternatively, this file may be used under the terms of the GNU Lesser
+** General Public License version 2.1 or version 3 as published by the Free
+** Software Foundation and appearing in the file LICENSE.LGPLv21 and
+** LICENSE.LGPLv3 included in the packaging of this file.  Please review the
+** following information to ensure the GNU Lesser General Public License
+** requirements will be met: https://www.gnu.org/licenses/lgpl.html and
+** http://www.gnu.org/licenses/old-licenses/lgpl-2.1.html.
+**
+** In addition, as a special exception, The Qt Company gives you certain additional
+** rights.  These rights are described in The Qt Company LGPL Exception
+** version 1.1, included in the file LGPL_EXCEPTION.txt in this package.
+**
+****************************************************************************/
+
+#include "fadingindicator.h"
+
+#include "stylehelper.h"
+
+#include <QGraphicsOpacityEffect>
+#include <QHBoxLayout>
+#include <QLabel>
+#include <QPainter>
+#include <QPixmap>
+#include <QPropertyAnimation>
+#include <QTimer>
+
+namespace Utils {
+namespace Internal {
+
+class FadingIndicatorPrivate : public QWidget
+{
+    Q_OBJECT
+
+public:
+    FadingIndicatorPrivate(QWidget *parent = 0)
+        : QWidget(parent)
+    {
+        m_effect = new QGraphicsOpacityEffect(this);
+        setGraphicsEffect(m_effect);
+        m_effect->setOpacity(1.);
+
+        m_label = new QLabel;
+        QFont font = m_label->font();
+        font.setPixelSize(45);
+        m_label->setFont(font);
+        QPalette pal = palette();
+        pal.setColor(QPalette::Foreground, pal.color(QPalette::Background));
+        m_label->setPalette(pal);
+        auto layout = new QHBoxLayout;
+        setLayout(layout);
+        layout->addWidget(m_label);
+    }
+
+    void setText(const QString &text)
+    {
+        m_pixmap = QPixmap();
+        m_label->setText(text);
+        adjustSize();
+        if (QWidget *parent = parentWidget())
+            move(parent->rect().center() - rect().center());
+    }
+
+    void setPixmap(const QString &uri)
+    {
+        m_label->hide();
+        m_pixmap.load(Utils::StyleHelper::dpiSpecificImageFile(uri));
+        resize(m_pixmap.size() / m_pixmap.devicePixelRatio());
+        if (QWidget *parent = parentWidget())
+            move(parent->rect().center() - rect().center());
+    }
+
+    void run(int ms)
+    {
+        show();
+        raise();
+        QTimer::singleShot(ms, this, SLOT(runInternal()));
+    }
+
+protected:
+    void paintEvent(QPaintEvent *)
+    {
+        QPainter p(this);
+        p.setRenderHint(QPainter::Antialiasing);
+        if (!m_pixmap.isNull()) {
+            p.drawPixmap(rect(), m_pixmap);
+        } else {
+            p.setBrush(palette().color(QPalette::Foreground));
+            p.setPen(Qt::NoPen);
+            p.drawRoundedRect(rect(), 15, 15);
+        }
+    }
+
+private slots:
+    void runInternal()
+    {
+        QPropertyAnimation *anim = new QPropertyAnimation(m_effect, "opacity", this);
+        anim->setDuration(200);
+        anim->setEndValue(0.);
+        connect(anim, SIGNAL(finished()), this, SLOT(deleteLater()));
+        anim->start(QAbstractAnimation::DeleteWhenStopped);
+    }
+
+private:
+    QGraphicsOpacityEffect *m_effect;
+    QLabel *m_label;
+    QPixmap m_pixmap;
+};
+
+} // Internal
+
+namespace FadingIndicator {
+
+void showText(QWidget *parent, const QString &text)
+{
+    auto indicator = new Internal::FadingIndicatorPrivate(parent);
+    indicator->setText(text);
+    indicator->run(1000); // deletes itself
+}
+
+void showPixmap(QWidget *parent, const QString &pixmap)
+{
+    auto indicator = new Internal::FadingIndicatorPrivate(parent);
+    indicator->setPixmap(pixmap);
+    indicator->run(300); // deletes itself
+}
+
+} // FadingIndicator
+} // Utils
+
+#include "fadingindicator.moc"