1 /*
2 *
3 * Copyright (c) 2009 Edward Apap <schumifer@hotmail.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 Free Software
17 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
18 */
19
20 #include "kcanvaspreview.h"
21
22 #include <QMouseEvent>
23 #include <QPainter>
24 #include <QCursor>
25
KCanvasPreview(QWidget * parent)26 KCanvasPreview::KCanvasPreview(QWidget * parent) : QWidget(parent), m_dragging(false)
27 {
28 setMouseTracking(true);
29 }
30
~KCanvasPreview()31 KCanvasPreview::~KCanvasPreview()
32 {
33 }
34
paintEvent(QPaintEvent *)35 void KCanvasPreview::paintEvent(QPaintEvent *)
36 {
37 QPainter p(this);
38
39 double scale = scalingFactor();
40
41 m_xCanvasOffset = (width() - scale * m_width) / 2.0;
42 m_yCanvasOffset = (height() - scale * m_height) / 2.0;
43
44 p.fillRect(m_xCanvasOffset, m_yCanvasOffset, m_width * scale, m_height * scale, QBrush(Qt::white));
45 p.setPen(QPen(Qt::red));
46 p.drawRect(m_xCanvasOffset + m_xOffset * scale, m_yCanvasOffset + m_yOffset * scale, m_imageWidth * scale, m_imageHeight * scale);
47 }
48
mousePressEvent(QMouseEvent * event)49 void KCanvasPreview::mousePressEvent(QMouseEvent *event)
50 {
51 if (isInRegion(event->pos())) {
52 m_dragging = true;
53 m_prevDragPoint = event->pos();
54 }
55 }
56
mouseReleaseEvent(QMouseEvent *)57 void KCanvasPreview::mouseReleaseEvent(QMouseEvent *)
58 {
59 m_dragging = false;
60 }
61
mouseMoveEvent(QMouseEvent * event)62 void KCanvasPreview::mouseMoveEvent(QMouseEvent *event)
63 {
64 if (m_dragging) {
65 // calculate new image offset
66 double scale = scalingFactor();
67
68 int newXOffset = ((event->pos().x() - m_prevDragPoint.x()) / scale) + m_xOffset;
69 int newYOffset = ((event->pos().y() - m_prevDragPoint.y()) / scale) + m_yOffset;
70
71 m_prevDragPoint = event->pos();
72
73 emit sigModifiedXOffset(newXOffset);
74 emit sigModifiedYOffset(newYOffset);
75 } else {
76 QCursor cursor;
77
78 if (isInRegion(event->pos())) {
79 cursor.setShape(Qt::SizeAllCursor);
80 } else {
81 cursor.setShape(Qt::ArrowCursor);
82 }
83
84 setCursor(cursor);
85 }
86 }
87
isInRegion(QPoint point)88 bool KCanvasPreview::isInRegion(QPoint point)
89 {
90 double scale = scalingFactor();
91
92 if ((point.x() >= (m_xOffset * scale) + m_xCanvasOffset) && (point.x() < ((m_xOffset + m_imageWidth) * scale) + m_xCanvasOffset) &&
93 (point.y() >= (m_yOffset * scale) + m_yCanvasOffset) && (point.y() < ((m_yOffset + m_imageHeight) * scale) + m_yCanvasOffset)) {
94 return true;
95 }
96
97 return false;
98 }
99
scalingFactor()100 double KCanvasPreview::scalingFactor()
101 {
102 // take into account offset frame size to show when the canvas has been shrinked
103 const int maxHeight = (m_height > m_imageHeight) ? m_height : m_imageHeight;
104 const int maxWidth = (m_width > m_imageWidth) ? m_width : m_imageWidth;
105
106 const double xScale = (double)(height() - 1) / maxHeight;
107 const double yScale = (double)(width() - 1) / maxWidth;
108
109 return (xScale < yScale) ? xScale : yScale;
110 }
111
setImageSize(qint32 w,qint32 h)112 void KCanvasPreview::setImageSize(qint32 w, qint32 h)
113 {
114 m_imageWidth = w;
115 m_imageHeight = h;
116
117 update();
118 }
119
setCanvasSize(qint32 w,qint32 h)120 void KCanvasPreview::setCanvasSize(qint32 w, qint32 h)
121 {
122 m_width = w;
123 m_height = h;
124
125 update();
126 }
127
setImageOffset(qint32 x,qint32 y)128 void KCanvasPreview::setImageOffset(qint32 x, qint32 y)
129 {
130 m_xOffset = x;
131 m_yOffset = y;
132
133 update();
134 }
135