Support for drag and drop (#54)

Added support for drag and drop

---------

Co-authored-by: Leonardo Seiji Oyama <oyama@coter.eb.mil.br>

CMakeLists.txt

@@ -22,6 +22,7 @@ if (${BUILD_EXAMPLES})
   add_subdirectory(samples/moving-objects)
   add_subdirectory(samples/mouse-actions)
   add_subdirectory(samples/camera-actions)
+  add_subdirectory(samples/drag-and-drop)
 else ()
   message(STATUS "Disabled building of examples")
 endif ()

QGeoView.pro

@@ -16,4 +16,5 @@ SUBDIRS = \
     samples/custom-tiles \
     samples/moving-objects \
     samples/mouse-actions \
-    samples/camera-actions
+    samples/camera-actions \
+	samples/drag-and-drop

lib/include/QGeoView/QGVMap.h

@@ -18,6 +18,7 @@
 
 #pragma once
 
+#include <QMimeData>
 #include <QWidget>
 
 #include "QGVCamera.h"
@@ -104,11 +105,13 @@ class QGV_LIB_DECL QGVMap : public QWidget
     void mapMouseMove(QPointF projPos);
     void mapMousePress(QPointF projPos);
     void mapMouseDoubleClicked(QPointF projPos);
+    void dropOnMap(QGV::GeoPos pos, const QMimeData* data);
 
 private:
     QScopedPointer<QGVProjection> mProjection;
     QScopedPointer<QGVMapQGView> mQGView;
     QScopedPointer<QGVItem> mRootItem;
     QList<QGVWidget*> mWidgets;
     QSet<QGVItem*> mSelections;
+    void handleDropDataOnQGVMapQGView(QPointF position, const QMimeData* dropData);
 };

lib/include/QGeoView/QGVMapQGView.h

@@ -23,8 +23,14 @@
 #include "QGVMapQGItem.h"
 #include "QGVMapRubberBand.h"
 
+
+#include <QDragEnterEvent>
+#include <QDragLeaveEvent>
+#include <QDragMoveEvent>
+#include <QDropEvent>
 #include <QGraphicsView>
 #include <QMenu>
+#include <QMimeData>
 
 class QGVMap;
 
@@ -45,6 +51,9 @@ class QGV_LIB_DECL QGVMapQGView : public QGraphicsView
     void setScaleLimits(double minScale, double maxScale);
     void cleanState();
 
+Q_SIGNALS:
+    void dropData(QPointF position, const QMimeData* dropData);
+
 private:
     QRectF viewRect() const;
     void changeState(QGV::MapState state);
@@ -83,6 +92,10 @@ class QGV_LIB_DECL QGVMapQGView : public QGraphicsView
     void resizeEvent(QResizeEvent* event) override final;
     void showEvent(QShowEvent* event) override final;
     void keyPressEvent(QKeyEvent* event) override final;
+    void dragEnterEvent(QDragEnterEvent* event) override final;
+    void dragMoveEvent(QDragMoveEvent* event) override final;
+    void dropEvent(QDropEvent* event) override final;
+    void dragLeaveEvent(QDragLeaveEvent* event) override final;
 
 private:
     QGVMap* mGeoMap;

lib/src/QGVMap.cpp

@@ -55,6 +55,7 @@ QGVMap::QGVMap(QWidget* parent)
     layout()->addWidget(mQGView.data());
     layout()->setContentsMargins(0, 0, 0, 0);
     refreshProjection();
+    connect(mQGView.data(), &QGVMapQGView::dropData, this, &QGVMap::handleDropDataOnQGVMapQGView);
 }
 
 QGVMap::~QGVMap()
@@ -381,6 +382,13 @@ void QGVMap::mousePressEvent(QMouseEvent* event)
     QWidget::mousePressEvent(event);
 }
 
+void QGVMap::handleDropDataOnQGVMapQGView(QPointF position, const QMimeData* dropData)
+{
+    const auto mapToProjectionPos = mapToProj(QPoint(position.rx(), position.ry()));
+    auto geoPos = getProjection()->projToGeo(mapToProjectionPos);
+    Q_EMIT dropOnMap(geoPos, dropData);
+}
+
 void QGVMap::mouseDoubleClickEvent(QMouseEvent* event)
 {
     if (hasMouseTracking()) {

lib/src/QGVMapQGView.cpp

@@ -66,6 +66,7 @@ QGVMapQGView::QGVMapQGView(QGVMap* geoMap)
     setCacheMode(QGraphicsView::CacheBackground);
     setMouseTracking(true);
     setBackgroundBrush(QBrush(Qt::lightGray));
+    setAcceptDrops(true);
 }
 
 void QGVMapQGView::setMouseActions(QGV::MouseActions actions)
@@ -599,3 +600,29 @@ void QGVMapQGView::keyPressEvent(QKeyEvent* event)
 {
     QWidget::keyPressEvent(event);
 }
+
+void QGVMapQGView::dragEnterEvent(QDragEnterEvent* event)
+{
+    event->accept();
+}
+
+void QGVMapQGView::dragMoveEvent(QDragMoveEvent* event)
+{
+    event->accept();
+}
+
+void QGVMapQGView::dropEvent(QDropEvent* event)
+{
+#if QT_VERSION >= QT_VERSION_CHECK(6, 0, 0)
+    Q_EMIT dropData(event->position(), event->mimeData());
+#else
+    QPointF dropPoint = event->posF();
+    Q_EMIT dropData(dropPoint, event->mimeData());
+#endif
+    event->accept();
+}
+
+void QGVMapQGView::dragLeaveEvent(QDragLeaveEvent* event)
+{
+    event->accept();
+}

samples/drag-and-drop/CMakeLists.txt

@@ -0,0 +1,37 @@
+set(CMAKE_CXX_STANDARD 11)
+
+set(CMAKE_AUTOMOC ON)
+set(CMAKE_AUTORCC ON)
+set(CMAKE_AUTOUIC ON)
+set(CMAKE_INCLUDE_CURRENT_DIR ON)
+
+# Set the QT version
+find_package(Qt6 COMPONENTS Core QUIET)
+if (NOT Qt6_FOUND)
+    set(QT_VERSION 5 CACHE STRING "Qt version for QGeoView")
+else()
+    set(QT_VERSION 6 CACHE STRING "Qt version for QGeoView")
+endif()
+
+find_package(Qt${QT_VERSION} REQUIRED COMPONENTS
+    Core
+    Gui
+    Widgets
+    Network
+)
+
+add_executable(qgeoview-samples-drag-and-drop
+    main.cpp
+    mainwindow.h
+    mainwindow.cpp
+)
+
+target_link_libraries(qgeoview-samples-drag-and-drop
+    PRIVATE
+    Qt${QT_VERSION}::Core
+    Qt${QT_VERSION}::Network
+    Qt${QT_VERSION}::Gui
+    Qt${QT_VERSION}::Widgets
+    QGeoView
+    qgeoview-samples-shared
+)

samples/drag-and-drop/drag-and-drop.pro

@@ -0,0 +1,15 @@
+TARGET = qgeoview-samples-drag-and-drop
+TEMPLATE = app
+CONFIG-= console
+
+QT += gui widgets network
+
+include(../lib.pri)
+include(../shared.pri)
+
+SOURCES += \
+    main.cpp \
+    mainwindow.cpp
+
+HEADERS += \
+    mainwindow.h

samples/drag-and-drop/main.cpp

@@ -0,0 +1,37 @@
+/***************************************************************************
+ * QGeoView is a Qt / C ++ widget for visualizing geographic data.
+ * Copyright (C) 2018-2023 Andrey Yaroshenko.
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU Lesser General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public License
+ * along with this program; if not, see https://www.gnu.org/licenses.
+ ****************************************************************************/
+
+#include <QApplication>
+#include <QCommandLineParser>
+
+#include "mainwindow.h"
+
+int main(int argc, char* argv[])
+{
+    QApplication app(argc, argv);
+    app.setApplicationName("QGeoView Samples");
+
+    QCommandLineParser parser;
+    parser.addHelpOption();
+    parser.addVersionOption();
+    parser.process(app);
+
+    MainWindow window;
+    window.show();
+    return app.exec();
+}

samples/drag-and-drop/mainwindow.cpp

@@ -0,0 +1,143 @@
+/***************************************************************************
+ * QGeoView is a Qt / C ++ widget for visualizing geographic data.
+ * Copyright (C) 2018-2023 Andrey Yaroshenko.
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU Lesser General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public License
+ * along with this program; if not, see https://www.gnu.org/licenses.
+ ****************************************************************************/
+
+#include "mainwindow.h"
+
+#include <QApplication>
+#include <QGuiApplication>
+#include <QHBoxLayout>
+#include <QIcon>
+#include <QTimer>
+#include <QTreeWidgetItem>
+
+//#include <QGeoView/QGVLayerBDGEx.h>
+#include <QGeoView/QGVLayerGoogle.h>
+#include <QGeoView/Raster/QGVIcon.h>
+#include <helpers.h>
+
+MainWindow::MainWindow(QWidget* parent)
+    : QMainWindow(parent)
+{
+    setWindowTitle("QGeoView Samples - drag and drop");
+    setCentralWidget(new QWidget());
+    centralWidget()->setLayout(new QHBoxLayout());
+
+    // setup tree widget
+    sampleTree = new QTreeWidget(this);
+    sampleTree->setDragEnabled(true); // enable dragging items from the tree
+    sampleTree->setMinimumWidth(200);
+    sampleTree->setMaximumWidth(250);
+
+    // setup data into the tree widget
+    sampleTree->setColumnCount(1);
+    sampleTree->setHeaderLabel("Sample Tree Items with Icons");
+
+    QTreeWidgetItem* itemArrowUp = new QTreeWidgetItem;
+    QIcon arrowUp_icon = QApplication::style()->standardIcon(QStyle::SP_ArrowUp);
+    itemArrowUp->setData(0, Qt::DisplayRole, "Arrow Up");
+    itemArrowUp->setData(0, Qt::DecorationRole, arrowUp_icon);
+    sampleTree->addTopLevelItem(itemArrowUp);
+
+    QTreeWidgetItem* itemArrowDown = new QTreeWidgetItem;
+    QIcon arrowDown_icon = QApplication::style()->standardIcon(QStyle::SP_ArrowDown);
+    itemArrowDown->setData(0, Qt::DisplayRole, "Arrow Down");
+    itemArrowDown->setData(0, Qt::DecorationRole, arrowDown_icon);
+    sampleTree->addTopLevelItem(itemArrowDown);
+
+    QTreeWidgetItem* itemArrowRight = new QTreeWidgetItem;
+    QIcon arrowRight_icon = QApplication::style()->standardIcon(QStyle::SP_ArrowRight);
+    itemArrowRight->setData(0, Qt::DisplayRole, "Arrow Right");
+    itemArrowRight->setData(0, Qt::DecorationRole, arrowRight_icon);
+    sampleTree->addTopLevelItem(itemArrowRight);
+
+    QTreeWidgetItem* itemArrowLeft = new QTreeWidgetItem;
+    QIcon arrowLeft_icon = QApplication::style()->standardIcon(QStyle::SP_ArrowLeft);
+    itemArrowLeft->setData(0, Qt::DisplayRole, "Arrow Left");
+    itemArrowLeft->setData(0, Qt::DecorationRole, arrowLeft_icon);
+    sampleTree->addTopLevelItem(itemArrowLeft);
+
+    centralWidget()->layout()->addWidget(sampleTree);
+
+    // QGeoView setup
+    Helpers::setupCachedNetworkAccessManager(this);
+    mMap = new QGVMap(this);
+
+    // Background layer
+    // QGVLayer * layerBDGExCTM250 = new QGVLayerBDGEx(QGV::BDGExLayer::ctm250);
+    // layerBDGExCTM250->setName("BDGEx CTM250");
+    // mMap->addItem(layerBDGExCTM250);
+
+    QGVLayer* layerGoogleSchema = new QGVLayerGoogle(QGV::TilesType::Schema);
+    layerGoogleSchema->setName("Google Schema");
+    mMap->addItem(layerGoogleSchema);
+
+    // initial area to show
+    QTimer::singleShot(500, this, &MainWindow::targetArea);
+    centralWidget()->layout()->addWidget(mMap); // add map to central widget
+
+    // handle drop of itens on map
+    connect(mMap, &QGVMap::dropOnMap, this, &MainWindow::handleDropOnMap);
+    iconsLayer = new QGVLayer();
+    mMap->addItem(iconsLayer);
+}
+
+MainWindow::~MainWindow()
+{
+}
+
+void MainWindow::targetArea()
+{
+    QGV::GeoPos geoPos(-23.55651916354534, -46.61844717963553);
+    auto scaleRect = QGV::GeoRect{
+        geoPos.latitude() - 0.33, geoPos.longitude() - 0.33, geoPos.latitude() + 0.33, geoPos.longitude() + 0.33
+    };
+    mMap->cameraTo(QGVCameraActions(mMap).scaleTo(scaleRect));
+    return;
+}
+
+void MainWindow::handleDropOnMap(QGV::GeoPos pos, const QMimeData* data)
+{
+    QByteArray encoded = data->data("application/x-qabstractitemmodeldatalist");
+    QDataStream stream(&encoded, QIODevice::ReadOnly);
+    QIcon iconDropped;
+    QString strDropped;
+    while (!stream.atEnd()) {
+        int row, col;
+        QMap<int, QVariant> roleDataMap;
+        stream >> row >> col >> roleDataMap;
+        for (auto i = 0; i < roleDataMap.size(); i++) {
+            std::string typeName = roleDataMap[i].typeName();
+            auto variant = roleDataMap[i];
+            if (typeName == "QString") {
+                strDropped = qvariant_cast<QString>(variant);
+            }
+            if (typeName == "QIcon") {
+                iconDropped = qvariant_cast<QIcon>(variant);
+            }
+        }
+    }
+    qDebug() << strDropped << "(lat, lon):" << pos.latToString() << pos.lonToString();
+    if (!iconDropped.isNull() && !strDropped.isEmpty()) {
+        auto* mIcon = new QGVIcon();
+        auto pixmap = iconDropped.pixmap(QSize(32, 32));
+        auto image = pixmap.toImage();
+        mIcon->loadImage(image);
+        mIcon->setGeometry(pos, QSizeF(32, 32));
+        iconsLayer->addItem(mIcon);
+    }
+}