add drop4

drop4/dialog.cpp

@@ -0,0 +1,54 @@
+#include "dialog.h"
+#include "ui_dialog.h"
+
+Dialog::Dialog(QWidget *parent) :
+    QDialog(parent),
+    ui(new Ui::Dialog)
+{
+    ui->setupUi(this);
+    listA = new ProjectListWidget;
+    listB = new ProjectListWidget;
+    buttonAToB = new QPushButton("->");
+    buttonBToA = new QPushButton("<-");
+
+    listA->addItem("Giosue Carducci");
+    listA->addItem("Eyvind Johnson");
+    listA->addItem("Sally Prudhomme");
+    listA->addItem("Henryk Sienkiewicz");
+    listA->addItem("Carl Spitteler");
+    listA->addItem("Rabindranath Tagore");
+    listA->addItem("Kawabata Yasunari");
+
+    listB->addItem("Rudolf Eucken");
+    listB->addItem("Anatole France");
+    listB->addItem("Rudyard Kipling");
+    listB->addItem("Thomas Mann");
+    listB->addItem("Eugene O'Neill");
+    listB->addItem("Sigrid Undset");
+
+
+    buttonAToB->setText("->");
+    buttonBToA->setText("<-");
+
+    QVBoxLayout *buttonLayout = new QVBoxLayout;
+    buttonLayout->addWidget(buttonAToB);
+    buttonLayout->addWidget(buttonBToA);
+
+    QHBoxLayout *hboxLayout = new QHBoxLayout;
+    hboxLayout->addWidget(listA);
+    hboxLayout->addLayout(buttonLayout);
+    hboxLayout->addWidget(listB);
+    setLayout(hboxLayout);
+
+    setFixedHeight( sizeHint().height() );
+
+    connect(buttonAToB, SIGNAL(clicked()),
+            this, SLOT(AToB_clicked()));
+    connect(buttonBToA, SIGNAL(clicked()),
+            this, SLOT(BToA_clicked()));
+}
+
+Dialog::~Dialog()
+{
+    delete ui;
+}

drop4/dialog.h

@@ -0,0 +1,31 @@
+#ifndef DIALOG_H
+#define DIALOG_H
+
+#include <QDialog>
+#include <QPushButton>
+#include <QVBoxLayout>
+#include <QHBoxLayout>
+#include "projectlistwidget.h"
+
+namespace Ui {
+class Dialog;
+}
+
+class Dialog : public QDialog
+{
+    Q_OBJECT
+
+public:
+    explicit Dialog(QWidget *parent = 0);
+    ~Dialog();
+
+private:
+    Ui::Dialog *ui;
+private:
+    QListWidget *listA;
+    QListWidget *listB;
+    QPushButton *buttonAToB;
+    QPushButton *buttonBToA;
+};
+
+#endif // DIALOG_H

drop4/dialog.ui

@@ -0,0 +1,20 @@
+<ui version="4.0">
+ <class>Dialog</class>
+ <widget class="QDialog" name="Dialog" >
+  <property name="geometry" >
+   <rect>
+    <x>0</x>
+    <y>0</y>
+    <width>400</width>
+    <height>300</height>
+   </rect>
+  </property>
+  <property name="windowTitle" >
+   <string>Dialog</string>
+  </property>
+ </widget>
+ <layoutDefault spacing="6" margin="11" />
+ <pixmapfunction></pixmapfunction>
+ <resources/>
+ <connections/>
+</ui>

drop4/drop4.pro

@@ -0,0 +1,22 @@
+#-------------------------------------------------
+#
+# Project created by QtCreator 2014-11-17T22:50:40
+#
+#-------------------------------------------------
+
+QT       += core gui
+
+greaterThan(QT_MAJOR_VERSION, 4): QT += widgets
+
+TARGET = drop4
+TEMPLATE = app
+
+
+SOURCES += main.cpp\
+        dialog.cpp \
+    projectlistwidget.cpp
+
+HEADERS  += dialog.h \
+    projectlistwidget.h
+
+FORMS    += dialog.ui

drop4/main.cpp

@@ -0,0 +1,11 @@
+#include "dialog.h"
+#include <QApplication>
+
+int main(int argc, char *argv[])
+{
+    QApplication a(argc, argv);
+    Dialog w;
+    w.show();
+
+    return a.exec();
+}

drop4/projectlistwidget.cpp

@@ -0,0 +1,79 @@
+#include "projectlistwidget.h"
+
+ProjectListWidget::ProjectListWidget(QWidget *parent)
+    : QListWidget(parent)
+{
+    //允许拖放
+        setAcceptDrops(true);
+}
+
+void ProjectListWidget::mousePressEvent(QMouseEvent *event)
+{
+    //获取鼠标按下时候的坐标
+    if (event->button() == Qt::LeftButton)
+        startPos = event->pos();
+    QListWidget::mousePressEvent(event);
+}
+
+void ProjectListWidget::mouseMoveEvent(QMouseEvent *event)
+{
+    if (event->buttons() & Qt::LeftButton) {
+        int distance = (event->pos() - startPos).manhattanLength();
+        //如果长度大于推荐的拖动起始距离，则认为是拖动(存在用户手抖的情况)
+        if (distance >= QApplication::startDragDistance())
+            performDrag();
+    }
+    QListWidget::mouseMoveEvent(event);
+}
+
+//有文件拖动到窗口上时，触发此dragEnterEvent事件
+void ProjectListWidget::dragEnterEvent(QDragEnterEvent *event)
+{
+    //当为同一个应用程序的一部分时，event->source()返回启动这个拖动窗口部件的指针
+    ProjectListWidget *source =
+            qobject_cast<ProjectListWidget *>(event->source());
+    if (source && source != this) {
+        //确认是一个移动的操作
+        event->setDropAction(Qt::MoveAction);
+        event->accept();
+    }
+}
+
+void ProjectListWidget::dragMoveEvent(QDragMoveEvent *event)
+{
+    ProjectListWidget *source =
+            qobject_cast<ProjectListWidget *>(event->source());
+    if (source && source != this) {
+        event->setDropAction(Qt::MoveAction);
+        event->accept();
+    }
+}
+
+void ProjectListWidget::dropEvent(QDropEvent *event)
+{
+    ProjectListWidget *source =
+            qobject_cast<ProjectListWidget *>(event->source());
+    if (source && source != this) {
+        //得到数据并增加到列表中
+        addItem(event->mimeData()->text());
+        event->setDropAction(Qt::MoveAction);
+        event->accept();
+    }
+}
+
+void ProjectListWidget::performDrag()
+{
+    //当前被拖动的选项
+    QListWidgetItem *item = currentItem();
+    if (item) {
+        QMimeData *mimeData = new QMimeData;
+        mimeData->setText(item->text());
+
+        QDrag *drag = new QDrag(this);
+        drag->setMimeData(mimeData);
+        drag->setPixmap(QPixmap(":/images/person.png"));
+        //进行拖动操作
+        if (drag->exec(Qt::MoveAction) == Qt::MoveAction)
+            delete item;
+    }
+}

drop4/projectlistwidget.h

@@ -0,0 +1,32 @@
+#ifndef PROJECTLISTWIDGET_H
+#define PROJECTLISTWIDGET_H
+
+#include <QListWidget>
+#include <QApplication>
+#include <QMimeData>
+#include <QDropEvent>
+#include <QDrag>
+#include <QDragEnterEvent>
+#include <QDragMoveEvent>
+#include <QMouseEvent>
+
+class ProjectListWidget : public QListWidget
+{
+    Q_OBJECT
+public:
+    ProjectListWidget(QWidget *parent = 0);
+
+protected:
+    void mousePressEvent(QMouseEvent *event);
+    void mouseMoveEvent(QMouseEvent *event);
+    void dragEnterEvent(QDragEnterEvent *event);
+    void dragMoveEvent(QDragMoveEvent *event);
+    void dropEvent(QDropEvent *event);
+
+private:
+    void performDrag();
+
+    QPoint startPos;
+};
+
+#endif // PROJECTLISTWIDGET_H