Added a custom widget for tagging dives

A custom tag widget has been added to MainTab.
Tags are seperated by a comma ",". The implementation
supports escaping a comma by using "\,".
While typing, the widget supports the user by suggesting
tags using a QCompleter.

Signed-off-by: Maximilian Güntner <maximilian.guentner@gmail.com>

qt-ui/groupedlineedit.cpp

@@ -0,0 +1,204 @@
+/*
+ * This file is part of the Nepomuk widgets collection
+ * Copyright (c) 2013 Denis Steckelmacher <steckdenis@yahoo.fr>
+ *
+ * This library is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Library General Public
+ * License version 2.1 as published by the Free Software Foundation,
+ * or any later version.
+ *
+ * This library 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
+ * Library General Public License for more details.
+ *
+ * You should have received a copy of the GNU Library General Public License
+ * along with this library; see the file COPYING.LIB.  If not, write to
+ * the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
+ * Boston, MA 02110-1301, USA.
+*/
+
+#include "groupedlineedit.h"
+
+#include <QtGui/QStyleOptionFrameV3>
+#include <QtGui/QFontMetrics>
+#include <QtGui/QApplication>
+#include <QtGui/QScrollBar>
+#include <QtGui/QTextDocument>
+#include <QtGui/QTextBlock>
+#include <QtGui/QTextLayout>
+#include <QtGui/QTextLine>
+#include <QtGui/QPainter>
+#include <QtGui/QPainterPath>
+#include <QtGui/QBrush>
+#include <QtGui/QColor>
+#include <QtGui/QPalette>
+
+struct GroupedLineEdit::Private
+{
+    struct Block {
+	    int start;
+	    int end;
+	    QString text;
+    };
+    QVector<Block> blocks;
+    QVector<QColor> colors;
+};
+
+GroupedLineEdit::GroupedLineEdit(QWidget* parent)
+: QPlainTextEdit(parent),
+  d(new Private)
+{
+    setWordWrapMode(QTextOption::NoWrap);
+    setSizePolicy(QSizePolicy::Expanding, QSizePolicy::Fixed);
+
+    setHorizontalScrollBarPolicy(Qt::ScrollBarAlwaysOff);
+    setVerticalScrollBarPolicy(Qt::ScrollBarAlwaysOff);
+
+    document()->setMaximumBlockCount(1);
+}
+
+
+GroupedLineEdit::~GroupedLineEdit()
+{
+    delete d;
+}
+
+QString GroupedLineEdit::text() const
+{
+    // Remove the block crosses from the text
+    return toPlainText();
+}
+
+int GroupedLineEdit::cursorPosition() const
+{
+    return textCursor().positionInBlock();
+}
+
+void GroupedLineEdit::addBlock(int start, int end)
+{
+    Private::Block block;
+
+    block.start = start;
+    block.end = end;
+    block.text = text().mid(start, end-start+1).trimmed();
+    d->blocks.append(block);
+    viewport()->update();
+}
+
+void GroupedLineEdit::addColor(QColor color)
+{
+    d->colors.append(color);
+}
+
+void GroupedLineEdit::removeAllColors()
+{
+	d->colors.clear();
+}
+
+QStringList GroupedLineEdit::getBlockStringList()
+{
+	QStringList retList;
+	Private::Block block;
+	foreach(block, d->blocks)
+		retList.append(block.text);
+	return retList;
+}
+
+void GroupedLineEdit::setCursorPosition(int position)
+{
+    QTextCursor c = textCursor();
+
+    c.setPosition(position, QTextCursor::MoveAnchor);
+
+    setTextCursor(c);
+}
+
+void GroupedLineEdit::setText(const QString &text)
+{
+    setPlainText(text);
+}
+
+void GroupedLineEdit::clear()
+{
+    QPlainTextEdit::clear();
+    removeAllBlocks();
+}
+
+void GroupedLineEdit::selectAll()
+{
+    QTextCursor c = textCursor();
+
+    c.select(QTextCursor::LineUnderCursor);
+
+    setTextCursor(c);
+}
+
+void GroupedLineEdit::removeAllBlocks()
+{
+    d->blocks.clear();
+    viewport()->update();
+}
+
+QSize GroupedLineEdit::sizeHint() const
+{
+    QSize rs(
+        40,
+        document()->findBlock(0).layout()->lineAt(0).height() +
+            document()->documentMargin() * 2 +
+            frameWidth() * 2
+    );
+
+    return rs;
+}
+
+QSize GroupedLineEdit::minimumSizeHint() const
+{
+    return sizeHint();
+}
+
+void GroupedLineEdit::keyPressEvent(QKeyEvent *e)
+{
+    switch (e->key()) {
+    case Qt::Key_Return:
+    case Qt::Key_Enter:
+        emit editingFinished();
+        return;
+    }
+
+    QPlainTextEdit::keyPressEvent(e);
+}
+
+void GroupedLineEdit::paintEvent(QPaintEvent *e)
+{
+
+    QTextLine line = document()->findBlock(0).layout()->lineAt(0);
+    QPainter painter(viewport());
+
+    painter.setRenderHint(QPainter::Antialiasing, true);
+    painter.setRenderHint(QPainter::HighQualityAntialiasing, true);
+
+    painter.fillRect(0, 0, viewport()->width(), viewport()->height(), palette().base());
+
+    QVectorIterator<QColor> i(d->colors);
+    i.toFront();
+    foreach (const Private::Block &block, d->blocks) {
+        qreal start_x = line.cursorToX(block.start, QTextLine::Trailing);
+        qreal end_x = line.cursorToX(block.end + 1, QTextLine::Leading);
+        QPainterPath path;
+        QRectF rectangle(
+            start_x - 1.0 - double(horizontalScrollBar()->value()),
+            1.0,
+            end_x - start_x + 2.0,
+            double(viewport()->height() - 2)
+        );
+        if (! i.hasNext())
+            i.toFront();
+        path.addRoundedRect(rectangle, 5.0, 5.0);
+        painter.setPen(i.peekNext());
+        painter.setBrush(i.next().lighter(180));
+        painter.drawPath(path);
+    }
+
+    QPlainTextEdit::paintEvent(e);
+}