Add QPdfSelection and QQuickPdfSelection

So now you can select text by mouse-drag and copy it to the clipboard.

Task-number: QTBUG-77509
Change-Id: I689ee4158974de8bc541c319a5a5cc2f8f3c2ae6
Reviewed-by: Michal Klocek <michal.klocek@qt.io>

6 files changed, 425 insertions, 0 deletions

diff --git a/src/pdf/quick/plugin.cpp b/src/pdf/quick/plugin.cpp
index 664ba51ab..72aa12d6a 100644
--- a/src/pdf/quick/plugin.cpp
+++ b/src/pdf/quick/plugin.cpp
@@ -40,6 +40,7 @@
 #include <QtQml/qqmlextensionplugin.h>
 #include "qquickpdfdocument_p.h"
 #include "qquickpdfsearchmodel_p.h"
+#include "qquickpdfselection_p.h"
 
 QT_BEGIN_NAMESPACE
 
@@ -81,6 +82,7 @@ public:
 
         qmlRegisterType<QQuickPdfDocument>(uri, 5, 15, "PdfDocument");
         qmlRegisterType<QQuickPdfSearchModel>(uri, 5, 15, "PdfSearchModel");
+        qmlRegisterType<QQuickPdfSelection>(uri, 5, 15, "PdfSelection");
 
         qmlRegisterType(QUrl("qrc:/qt-project.org/qtpdf/qml/PdfPageView.qml"), uri, 5, 15, "PdfPageView");
     }
diff --git a/src/pdf/quick/qml/PdfPageView.qml b/src/pdf/quick/qml/PdfPageView.qml
index b7f75f4c2..2f9c5ef99 100644
--- a/src/pdf/quick/qml/PdfPageView.qml
+++ b/src/pdf/quick/qml/PdfPageView.qml
@@ -51,10 +51,23 @@ Rectangle {
     property alias currentPage: image.currentFrame
     property alias pageCount: image.frameCount
     property alias searchString: searchModel.searchString
+    property alias selectedText: selection.text
     property alias status: image.status
 
     property real __pageScale: image.paintedWidth / document.pagePointSize(image.currentFrame).width
 
+    PdfSelection {
+        id: selection
+        document: paper.document
+        page: image.currentFrame
+        fromPoint: Qt.point(textSelectionDrag.centroid.pressPosition.x / paper.__pageScale, textSelectionDrag.centroid.pressPosition.y / paper.__pageScale)
+        toPoint: Qt.point(textSelectionDrag.centroid.position.x / paper.__pageScale, textSelectionDrag.centroid.position.y / paper.__pageScale)
+        hold: !textSelectionDrag.active && !tapHandler.pressed
+    }
+    function copySelectionToClipboard() {
+        selection.copyToClipboard()
+    }
+
     PdfSearchModel {
         id: searchModel
         document: paper.document
@@ -96,6 +109,14 @@ Rectangle {
                 paths: searchModel.matchGeometry
             }
         }
+        ShapePath {
+            fillColor: "orange"
+            scale: Qt.size(paper.__pageScale, paper.__pageScale)
+            PathMultiline {
+                id: selectionBoundaries
+                paths: selection.geometry
+            }
+        }
     }
     PinchHandler {
         id: pinch
@@ -116,4 +137,13 @@ Rectangle {
         acceptedButtons: Qt.MiddleButton
         snapMode: DragHandler.NoSnap
     }
+    DragHandler {
+        id: textSelectionDrag
+        acceptedDevices: PointerDevice.Mouse | PointerDevice.Stylus
+        target: null
+    }
+    TapHandler {
+        id: tapHandler
+        acceptedDevices: PointerDevice.Mouse | PointerDevice.Stylus
+    }
 }
diff --git a/src/pdf/quick/qquickpdfsearchmodel_p.h b/src/pdf/quick/qquickpdfsearchmodel_p.h
index 799ef825f..82a6289d0 100644
--- a/src/pdf/quick/qquickpdfsearchmodel_p.h
+++ b/src/pdf/quick/qquickpdfsearchmodel_p.h
@@ -99,5 +99,6 @@ private:
 QT_END_NAMESPACE
 
 QML_DECLARE_TYPE(QQuickPdfSearchModel)
+QML_DECLARE_TYPE(QPdfSelection)
 
 #endif // QQUICKPDFSEARCHMODEL_P_H
diff --git a/src/pdf/quick/qquickpdfselection.cpp b/src/pdf/quick/qquickpdfselection.cpp
new file mode 100644
index 000000000..d313820ba
--- /dev/null
+++ b/src/pdf/quick/qquickpdfselection.cpp
@@ -0,0 +1,268 @@
+/****************************************************************************
+**
+** Copyright (C) 2020 The Qt Company Ltd.
+** Contact: http://www.qt.io/licensing/
+**
+** This file is part of the QtPDF module of the Qt Toolkit.
+**
+** $QT_BEGIN_LICENSE:LGPL3$
+** 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 3 as published by the Free Software
+** Foundation and appearing in the file LICENSE.LGPLv3 included in the
+** packaging of this file. Please review the following information to
+** ensure the GNU Lesser General Public License version 3 requirements
+** will be met: https://www.gnu.org/licenses/lgpl.html.
+**
+** GNU General Public License Usage
+** Alternatively, this file may be used under the terms of the GNU
+** General Public License version 2.0 or later as published by the Free
+** Software Foundation and appearing in the file LICENSE.GPL included in
+** the packaging of this file. Please review the following information to
+** ensure the GNU General Public License version 2.0 requirements will be
+** met: http://www.gnu.org/licenses/gpl-2.0.html.
+**
+** $QT_END_LICENSE$
+**
+****************************************************************************/
+
+#include "qquickpdfselection_p.h"
+#include "qquickpdfdocument_p.h"
+#include <QClipboard>
+#include <QQuickItem>
+#include <QQmlEngine>
+#include <QStandardPaths>
+#include <private/qguiapplication_p.h>
+
+QT_BEGIN_NAMESPACE
+
+/*!
+    \qmltype PdfSelection
+    \instantiates QQuickPdfSelection
+    \inqmlmodule QtQuick.Pdf
+    \ingroup pdf
+    \brief A representation of a text selection within a PDF Document.
+    \since 5.15
+
+    PdfSelection provides the text string and its geometry within a bounding box
+    from one point to another.
+*/
+
+/*!
+    Constructs a SearchModel.
+*/
+QQuickPdfSelection::QQuickPdfSelection(QObject *parent)
+    : QObject(parent)
+{
+}
+
+QQuickPdfDocument *QQuickPdfSelection::document() const
+{
+    return m_document;
+}
+
+void QQuickPdfSelection::setDocument(QQuickPdfDocument *document)
+{
+    if (m_document == document)
+        return;
+
+    if (m_document) {
+        disconnect(m_document, &QQuickPdfDocument::sourceChanged,
+                   this, &QQuickPdfSelection::resetPoints);
+    }
+    m_document = document;
+    emit documentChanged();
+    resetPoints();
+    connect(m_document, &QQuickPdfDocument::sourceChanged,
+            this, &QQuickPdfSelection::resetPoints);
+}
+
+/*!
+    \qmlproperty list<list<point>> PdfSelection::geometry
+
+    A set of paths in a form that can be bound to the \c paths property of a
+    \l {QtQuick::PathMultiline}{PathMultiline} instance to render a batch of
+    rectangles around the text regions that are included in the selection:
+
+    \qml
+    PdfDocument {
+        id: doc
+    }
+    PdfSelection {
+        id: selection
+        document: doc
+        fromPoint: textSelectionDrag.centroid.pressPosition
+        toPoint: textSelectionDrag.centroid.position
+        hold: !textSelectionDrag.active
+    }
+    Shape {
+        ShapePath {
+            PathMultiline {
+                paths: selection.geometry
+            }
+        }
+    }
+    DragHandler {
+        id: textSelectionDrag
+        acceptedDevices: PointerDevice.Mouse | PointerDevice.Stylus
+        target: null
+    }
+    \endqml
+
+    \sa PathMultiline
+*/
+QVector<QPolygonF> QQuickPdfSelection::geometry() const
+{
+    return m_geometry;
+}
+
+void QQuickPdfSelection::resetPoints()
+{
+    bool wasHolding = m_hold;
+    m_hold = false;
+    setFromPoint(QPointF());
+    setToPoint(QPointF());
+    m_hold = wasHolding;
+}
+
+/*!
+    \qmlproperty int PdfSelection::page
+
+    The page number on which to search.
+
+    \sa QtQuick::Image::currentFrame
+*/
+int QQuickPdfSelection::page() const
+{
+    return m_page;
+}
+
+void QQuickPdfSelection::setPage(int page)
+{
+    if (m_page == page)
+        return;
+
+    m_page = page;
+    emit pageChanged();
+    resetPoints();
+}
+
+/*!
+    \qmlproperty point PdfSelection::fromPoint
+
+    The beginning location, in \l {https://en.wikipedia.org/wiki/Point_(typography)}{points}
+    from the upper-left corner of the page, from which to find selected text.
+    This can be bound to a scaled version of the \c centroid.pressPosition
+    of a \l DragHandler to begin selecting text from the position where the user
+    presses the mouse button and begins dragging, for example.
+*/
+QPointF QQuickPdfSelection::fromPoint() const
+{
+    return m_fromPoint;
+}
+
+void QQuickPdfSelection::setFromPoint(QPointF fromPoint)
+{
+    if (m_hold || m_fromPoint == fromPoint)
+        return;
+
+    m_fromPoint = fromPoint;
+    emit fromPointChanged();
+    updateResults();
+}
+
+/*!
+    \qmlproperty point PdfSelection::toPoint
+
+    The ending location, in \l {https://en.wikipedia.org/wiki/Point_(typography)}{points}
+    from the upper-left corner of the page, from which to find selected text.
+    This can be bound to a scaled version of the \c centroid.position
+    of a \l DragHandler to end selection of text at the position where the user
+    is currently dragging the mouse, for example.
+*/
+QPointF QQuickPdfSelection::toPoint() const
+{
+    return m_toPoint;
+}
+
+void QQuickPdfSelection::setToPoint(QPointF toPoint)
+{
+    if (m_hold || m_toPoint == toPoint)
+        return;
+
+    m_toPoint = toPoint;
+    emit toPointChanged();
+    updateResults();
+}
+
+/*!
+    \qmlproperty bool PdfSelection::hold
+
+    Controls whether to hold the existing selection regardless of changes to
+    \l fromPoint and \l toPoint. This property can be set to \c true when the mouse
+    or touchpoint is released, so that the selection is not lost due to the
+    point bindings changing.
+*/
+bool QQuickPdfSelection::hold() const
+{
+    return m_hold;
+}
+
+void QQuickPdfSelection::setHold(bool hold)
+{
+    if (m_hold == hold)
+        return;
+
+    m_hold = hold;
+    emit holdChanged();
+}
+
+/*!
+    \qmlproperty string PdfSelection::string
+
+    The string found.
+*/
+QString QQuickPdfSelection::text() const
+{
+    return m_text;
+}
+
+#if QT_CONFIG(clipboard)
+/*!
+    \qmlmethod void PdfSelection::copyToClipboard()
+
+    Copies plain text from the \l string property to the system clipboard.
+*/
+void QQuickPdfSelection::copyToClipboard() const
+{
+     QGuiApplication::clipboard()->setText(m_text);
+}
+#endif
+
+void QQuickPdfSelection::updateResults()
+{
+    if (!m_document)
+        return;
+    QPdfSelection sel = m_document->document().getSelection(m_page, m_fromPoint, m_toPoint);
+    if (sel.text() != m_text) {
+        m_text = sel.text();
+        if (QGuiApplication::clipboard()->supportsSelection())
+            sel.copyToClipboard(QClipboard::Selection);
+        emit textChanged();
+    }
+
+    if (sel.bounds() != m_geometry) {
+        m_geometry = sel.bounds();
+        emit geometryChanged();
+    }
+}
+
+QT_END_NAMESPACE
diff --git a/src/pdf/quick/qquickpdfselection_p.h b/src/pdf/quick/qquickpdfselection_p.h
new file mode 100644
index 000000000..a0e6d1a8d
--- /dev/null
+++ b/src/pdf/quick/qquickpdfselection_p.h
@@ -0,0 +1,122 @@
+/****************************************************************************
+**
+** Copyright (C) 2020 The Qt Company Ltd.
+** Contact: http://www.qt.io/licensing/
+**
+** This file is part of the QtPDF module of the Qt Toolkit.
+**
+** $QT_BEGIN_LICENSE:LGPL3$
+** 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 3 as published by the Free Software
+** Foundation and appearing in the file LICENSE.LGPLv3 included in the
+** packaging of this file. Please review the following information to
+** ensure the GNU Lesser General Public License version 3 requirements
+** will be met: https://www.gnu.org/licenses/lgpl.html.
+**
+** GNU General Public License Usage
+** Alternatively, this file may be used under the terms of the GNU
+** General Public License version 2.0 or later as published by the Free
+** Software Foundation and appearing in the file LICENSE.GPL included in
+** the packaging of this file. Please review the following information to
+** ensure the GNU General Public License version 2.0 requirements will be
+** met: http://www.gnu.org/licenses/gpl-2.0.html.
+**
+** $QT_END_LICENSE$
+**
+****************************************************************************/
+
+#ifndef QQUICKPDFSELECTION_P_H
+#define QQUICKPDFSELECTION_P_H
+
+//
+//  W A R N I N G
+//  -------------
+//
+// This file is not part of the Qt API.  It exists purely as an
+// implementation detail.  This header file may change from version to
+// version without notice, or even be removed.
+//
+// We mean it.
+//
+
+#include <QPointF>
+#include <QPolygonF>
+#include <QVariant>
+#include <QtQml/qqml.h>
+
+QT_BEGIN_NAMESPACE
+
+class QQuickPdfDocument;
+
+class QQuickPdfSelection : public QObject
+{
+    Q_OBJECT
+    Q_PROPERTY(QQuickPdfDocument *document READ document WRITE setDocument NOTIFY documentChanged)
+    Q_PROPERTY(int page READ page WRITE setPage NOTIFY pageChanged)
+    Q_PROPERTY(QPointF fromPoint READ fromPoint WRITE setFromPoint NOTIFY fromPointChanged)
+    Q_PROPERTY(QPointF toPoint READ toPoint WRITE setToPoint NOTIFY toPointChanged)
+    Q_PROPERTY(bool hold READ hold WRITE setHold NOTIFY holdChanged)
+
+    Q_PROPERTY(QString text READ text NOTIFY textChanged)
+    Q_PROPERTY(QVector<QPolygonF> geometry READ geometry NOTIFY geometryChanged)
+
+public:
+    explicit QQuickPdfSelection(QObject *parent = nullptr);
+
+    QQuickPdfDocument *document() const;
+    void setDocument(QQuickPdfDocument * document);
+    int page() const;
+    void setPage(int page);
+    QPointF fromPoint() const;
+    void setFromPoint(QPointF fromPoint);
+    QPointF toPoint() const;
+    void setToPoint(QPointF toPoint);
+    bool hold() const;
+    void setHold(bool hold);
+
+    QString text() const;
+    QVector<QPolygonF> geometry() const;
+
+#if QT_CONFIG(clipboard)
+    Q_INVOKABLE void copyToClipboard() const;
+#endif
+
+signals:
+    void documentChanged();
+    void pageChanged();
+    void fromPointChanged();
+    void toPointChanged();
+    void holdChanged();
+    void textChanged();
+    void geometryChanged();
+
+private:
+    void resetPoints();
+    void updateResults();
+
+private:
+    QQuickPdfDocument *m_document = nullptr;
+    QPointF m_fromPoint;
+    QPointF m_toPoint;
+    QString m_text;
+    QVector<QPolygonF> m_geometry;
+    int m_page = 0;
+    bool m_hold = false;
+
+    Q_DISABLE_COPY(QQuickPdfSelection)
+};
+
+QT_END_NAMESPACE
+
+QML_DECLARE_TYPE(QQuickPdfSelection)
+\
+#endif // QQUICKPDFSELECTION_P_H
diff --git a/src/pdf/quick/quick.pro b/src/pdf/quick/quick.pro
index cda768369..d999ffb0b 100644
--- a/src/pdf/quick/quick.pro
+++ b/src/pdf/quick/quick.pro
@@ -16,10 +16,12 @@ SOURCES += \
     plugin.cpp \
     qquickpdfdocument.cpp \
     qquickpdfsearchmodel.cpp \
+    qquickpdfselection.cpp \
 
 HEADERS += \
     qquickpdfdocument_p.h \
     qquickpdfsearchmodel_p.h \
+    qquickpdfselection_p.h \
 
 QT += pdf quick-private gui gui-private core core-private qml qml-private