ZoomWheel.cpp
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1 /* Copyright (C) 2008 National Institute For Space Research (INPE) - Brazil.
2 
3  This file is part of the TerraLib - a Framework for building GIS enabled applications.
4 
5  TerraLib is free software: you can redistribute it and/or modify
6  it under the terms of the GNU Lesser General Public License as published by
7  the Free Software Foundation, either version 3 of the License,
8  or (at your option) any later version.
9 
10  TerraLib 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 Lesser General Public License for more details.
14 
15  You should have received a copy of the GNU Lesser General Public License
16  along with TerraLib. See COPYING. If not, write to
17  TerraLib Team at <terralib-team@terralib.org>.
18  */
19 
20 /*!
21  \file terralib/qt/widgets/tools/ZoomWheel.cpp
22 
23  \brief This class implements a concrete tool to geographic zoom operation using the mouse wheel.
24 */
25 
26 // TerraLib
27 #include "../canvas/MapDisplay.h"
28 #include "ZoomWheel.h"
29 
30 // Qt
31 #include <QPixmap>
32 #include <QWheelEvent>
33 
34 te::qt::widgets::ZoomWheel::ZoomWheel(te::qt::widgets::MapDisplay* display, const double& zoomFactor, const bool& centralize, QObject* parent)
35  : Zoom(display, zoomFactor, In, parent)
36  , m_centralize(centralize)
37 {
38 }
39 
41 
43 {
44  if(watched != m_display)
45  return false;
46 
47  switch(e->type())
48  {
49  case QEvent::Wheel:
50  {
51  QWheelEvent* wheelEvent = static_cast<QWheelEvent*>(e);
52  wheelEvent->delta() > 0 ? setZoomType(In) : setZoomType(Out);
53 
54  QPixmap* draft = m_display->getDraftPixmap();
55  draft->fill(Qt::transparent);
56 
57  QPointF qPos;
58  if(m_centralize == false)
59  {
60  qPos = m_display->transform(wheelEvent->pos());
61  }
62 
63  applyZoom(qPos);
64 
65  return true;
66  }
67 
68  default:
69  return Zoom::eventFilter(watched, e);
70  }
71 }
This is a utility class to geographic zoom operation.
Definition: Zoom.h:49
This class implements a concrete tool to geographic zoom operation using the mouse wheel...
void setZoomType(const ZoomType &type)
Sets the zoom operation type.
Definition: Zoom.cpp:44
A widget to control the display of a set of layers.
bool m_centralize
If TRUE, the reference that will be used will be the center of the map display extent. If FALSE, the position of the wheel will be used as reference.
Definition: ZoomWheel.h:85
virtual bool eventFilter(QObject *watched, QEvent *e)
Filters events if this object has been installed as an event filter for the watched object...
virtual QPointF transform(const QPointF &p)
Transforms the given point, in screen coordinates, to a point in world coordinates.
virtual QPixmap * getDraftPixmap() const
It returns the map display draft pixmap.
bool eventFilter(QObject *watched, QEvent *e)
Filters events if this object has been installed as an event filter for the watched object...
Definition: ZoomWheel.cpp:42
MapDisplay * m_display
The map display associated with the tool.
Definition: AbstractTool.h:171
ZoomWheel(MapDisplay *display, const double &zoomFactor=2.0, const bool &centralize=true, QObject *parent=0)
It constructs a zoom wheel tool associated with the given map display.
Definition: ZoomWheel.cpp:34
void applyZoom(const QPointF &point=QPointF(), bool centralize=true)
Performs the zoom operation on map display, considering the zoom factor, zoom type and the given poin...
Definition: Zoom.cpp:49