src/views/dolphintreeview.h

   1 /***************************************************************************
   2  *   Copyright (C) 2010 by Peter Penz <peter.penz19@gmail.com>             *
   3  *   Copyright (C) 2008 by Simon St. James <kdedevel@etotheipiplusone.com> *
   4  *                                                                         *
   5  *   This program is free software; you can redistribute it and/or modify  *
   6  *   it under the terms of the GNU General Public License as published by  *
   7  *   the Free Software Foundation; either version 2 of the License, or     *
   8  *   (at your option) any later version.                                   *
   9  *                                                                         *
  10  *   This program is distributed in the hope that it will be useful,       *
  11  *   but WITHOUT ANY WARRANTY; without even the implied warranty of        *
  12  *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the         *
  13  *   GNU General Public License for more details.                          *
  14  *                                                                         *
  15  *   You should have received a copy of the GNU General Public License     *
  16  *   along with this program; if not, write to the                         *
  17  *   Free Software Foundation, Inc.,                                       *
  18  *   51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA            *
  19  ***************************************************************************/
  20
  21 #ifndef DOLPHINTREEVIEW_H
  22 #define DOLPHINTREEVIEW_H
  23
  24 #include <QTreeView>
  25 #include <libdolphin_export.h>
  26
  27 /**
  28  * @brief Extends QTreeView by a custom selection- and hover-mechanism.
  29  *
  30  * QTreeView does not respect the width of a cell for the hover-feedback
  31  * and when selecting items. DolphinTreeView improves this by respecting the
  32  * content-width of the first column. The selection-mechanism also
  33  * respects the content-width.
  34  */
  35 class LIBDOLPHINPRIVATE_EXPORT DolphinTreeView : public QTreeView
  36 {
  37     Q_OBJECT
  38
  39 public:
  40     explicit DolphinTreeView(QWidget* parent = 0);
  41     virtual ~DolphinTreeView();
  42
  43     virtual QModelIndex indexAt (const QPoint& point) const;
  44     virtual QRegion visualRegionForSelection(const QItemSelection& selection) const;
  45
  46 protected:
  47     /**
  48      * @return True, if the item with the index \p index accepts a drop. In this
  49      *         case a visual feedback for the user is given during dragging. Per
  50      *         default false is returned.
  51      */
  52     virtual bool acceptsDrop(const QModelIndex& index) const;
  53
  54     virtual bool event(QEvent* event);
  55     virtual void mousePressEvent(QMouseEvent* event);
  56     virtual void mouseMoveEvent(QMouseEvent* event);
  57     virtual void mouseReleaseEvent(QMouseEvent* event);
  58     virtual void startDrag(Qt::DropActions supportedActions);
  59     virtual void dragEnterEvent(QDragEnterEvent* event);
  60     virtual void dragMoveEvent(QDragMoveEvent* event);
  61     virtual void dragLeaveEvent(QDragLeaveEvent* event);
  62     virtual void paintEvent(QPaintEvent* event);
  63     virtual void keyPressEvent(QKeyEvent* event);
  64     virtual void keyReleaseEvent(QKeyEvent* event);
  65     virtual void currentChanged(const QModelIndex& current, const QModelIndex& previous);
  66     virtual void setSelection(const QRect& rect, QItemSelectionModel::SelectionFlags command);
  67     virtual void scrollTo(const QModelIndex& index, ScrollHint hint = EnsureVisible);
  68
  69 private slots:
  70     /**
  71      * If the elastic band is currently shown, update the elastic band based on
  72      * the current mouse position and ensure that the selection is the set of items
  73      * intersecting it.
  74      */
  75     void updateElasticBandSelection();
  76
  77     /**
  78      * Updates the destination \a destination from
  79      * the elastic band to the current mouse position and triggers
  80      * an update.
  81      */
  82     void updateElasticBand();
  83
  84     /**
  85      * Returns the rectangle for the elastic band dependent from the
  86      * origin \a origin, the current destination
  87      * \a destination and the viewport position.
  88      */
  89     QRect elasticBandRect() const;
  90
  91 private:
  92     /**
  93      * Returns true, if \a pos is within the expanding toggle of a tree.
  94      */
  95     bool isAboveExpandingToggle(const QPoint& pos) const;
  96
  97 private:
  98     bool m_keyPressed;        // true if a key is pressed currently; info used by currentChanged()
  99     bool m_expandingTogglePressed;
 100     bool m_useDefaultIndexAt; // true, if QTreeView::indexAt() should be used
 101     bool m_ignoreScrollTo;    // true if calls to scrollTo(...) should do nothing.
 102
 103     QRect m_dropRect;
 104
 105     struct ElasticBand
 106     {
 107         ElasticBand();
 108
 109         // Elastic band origin and destination coordinates are relative to t
 110         // he origin of the view, not the viewport.
 111         bool show;
 112         QPoint origin;
 113         QPoint destination;
 114
 115         // Optimization mechanisms for use with elastic band selection.
 116         // Basically, allow "incremental" updates to the selection based
 117         // on the last elastic band shape.
 118         QPoint lastSelectionOrigin;
 119         QPoint lastSelectionDestination;
 120
 121         // If true, compute the set of selected elements from scratch (slower)
 122         bool ignoreOldInfo;
 123
 124         // Edges of the filenames that are closest to the edges of oldSelectionRect.
 125         // Used to decide whether horizontal changes in the elastic band are likely
 126         // to require us to re-check which items are selected.
 127         int outsideNearestLeftEdge;
 128         int outsideNearestRightEdge;
 129         int insideNearestLeftEdge;
 130         int insideNearestRightEdge;
 131         // The set of items that were selected at the time this band was shown.
 132         // NOTE: Unless CTRL was pressed when the band was created, this is always empty.
 133         QItemSelection originalSelection;
 134     } m_band;
 135 };
 136
 137 #endif