SqlTextEdit: Support opening files by drag and drop

When dropping a file on the editor widget try to open and read it.

src/sqltextedit.cpp

@@ -7,6 +7,7 @@
 #include <QScrollBar>
 #include <QPainter>
 #include <QTextBlock>
+#include <QUrl>
 
 SqlTextEdit::SqlTextEdit(QWidget* parent) :
     QPlainTextEdit(parent), m_Completer(0), m_defaultCompleterModel(0)
@@ -181,6 +182,22 @@ void SqlTextEdit::LineNumberArea::paintEvent(QPaintEvent* event)
     }
 }
 
+void SqlTextEdit::dropEvent(QDropEvent* e)
+{
+    QList<QUrl> urls = e->mimeData()->urls();
+    if(urls.isEmpty())
+        return QPlainTextEdit::dropEvent(e);
+
+    QString file = urls.first().toLocalFile();
+    if(!QFile::exists(file))
+        return;
+
+    QFile f(file);
+    f.open(QIODevice::ReadOnly);
+    setPlainText(f.readAll());
+    f.close();
+}
+
 QSize SqlTextEdit::LineNumberArea::sizeHint() const
 {
     return QSize(parent->lineNumberAreaWidth(), 0);

src/sqltextedit.h

@@ -32,6 +32,7 @@ protected:
     void keyPressEvent(QKeyEvent *e);
     void focusInEvent(QFocusEvent *e);
     void resizeEvent(QResizeEvent* event);
+    void dropEvent(QDropEvent* e);
 
     void lineNumberAreaPaintEvent(QPaintEvent* event);
     int lineNumberAreaWidth();