gwenview/lib/croptool.cpp

   1 // vim: set tabstop=4 shiftwidth=4 noexpandtab:
   2 /*
   3 Gwenview: an image viewer
   4 Copyright 2007 Aurélien Gâteau <aurelien.gateau@free.fr>
   5
   6 This program is free software; you can redistribute it and/or
   7 modify it under the terms of the GNU General Public License
   8 as published by the Free Software Foundation; either version 2
   9 of the License, or (at your option) any later version.
  10
  11 This program is distributed in the hope that it will be useful,
  12 but WITHOUT ANY WARRANTY; without even the implied warranty of
  13 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  14 GNU General Public License for more details.
  15
  16 You should have received a copy of the GNU General Public License
  17 along with this program; if not, write to the Free Software
  18 Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
  19
  20 */
  21 // Self
  22 #include "croptool.h"
  23
  24 // Qt
  25 #include <QMouseEvent>
  26 #include <QPainter>
  27 #include <QRect>
  28
  29 // KDE
  30 #include <kdebug.h>
  31
  32 // Local
  33 #include "imageview.h"
  34
  35 static const int HANDLE_RADIUS = 5;
  36
  37 static const int UNINITIALIZED_X = -1;
  38
  39 namespace Gwenview {
  40
  41
  42 enum CropHandle {
  43         CH_None,
  44         CH_Top = 1,
  45         CH_Left = 2,
  46         CH_Right = 4,
  47         CH_Bottom = 8,
  48         CH_TopLeft = CH_Top | CH_Left,
  49         CH_BottomLeft = CH_Bottom | CH_Left,
  50         CH_TopRight = CH_Top | CH_Right,
  51         CH_BottomRight = CH_Bottom | CH_Right,
  52         CH_Content = 16
  53 };
  54
  55
  56 struct CropToolPrivate {
  57         CropTool* mCropTool;
  58         QRect mRect;
  59         QList<CropHandle> mCropHandleList;
  60         CropHandle mMovingHandle;
  61         QPoint mLastMouseMovePos;
  62         double mCropRatio;
  63
  64         QRect handleViewportRect(CropHandle handle) {
  65                 QRect viewportCropRect = mCropTool->imageView()->mapToViewport(mRect);
  66                 int left, top;
  67                 if (handle & CH_Top) {
  68                         top = viewportCropRect.top() - HANDLE_RADIUS;
  69                 } else if (handle & CH_Bottom) {
  70                         top = viewportCropRect.bottom() - HANDLE_RADIUS;
  71                 } else {
  72                         top = viewportCropRect.top() + viewportCropRect.height() / 2 - HANDLE_RADIUS;
  73                 }
  74
  75                 if (handle & CH_Left) {
  76                         left = viewportCropRect.left() - HANDLE_RADIUS;
  77                 } else if (handle & CH_Right) {
  78                         left = viewportCropRect.right() - HANDLE_RADIUS;
  79                 } else {
  80                         left = viewportCropRect.left() + viewportCropRect.width() / 2 - HANDLE_RADIUS;
  81                 }
  82
  83                 return QRect(left, top, HANDLE_RADIUS * 2 + 1, HANDLE_RADIUS * 2 + 1);
  84         }
  85
  86
  87         CropHandle handleAt(const QPoint& pos) {
  88                 Q_FOREACH(const CropHandle& handle, mCropHandleList) {
  89                         QRect rect = handleViewportRect(handle);
  90                         if (rect.contains(pos)) {
  91                                 return handle;
  92                         }
  93                 }
  94                 QRect viewportCropRect = mCropTool->imageView()->mapToViewport(mRect);
  95                 if (viewportCropRect.contains(pos)) {
  96                         return CH_Content;
  97                 }
  98                 return CH_None;
  99         }
 100
 101         void updateCursor(CropHandle handle, bool buttonDown) {
 102                 Qt::CursorShape shape;
 103                 switch (handle) {
 104                 case CH_TopLeft:
 105                 case CH_BottomRight:
 106                         shape = Qt::SizeFDiagCursor;
 107                         break;
 108
 109                 case CH_TopRight:
 110                 case CH_BottomLeft:
 111                         shape = Qt::SizeBDiagCursor;
 112                         break;
 113
 114                 case CH_Left:
 115                 case CH_Right:
 116                         shape = Qt::SizeHorCursor;
 117                         break;
 118
 119                 case CH_Top:
 120                 case CH_Bottom:
 121                         shape = Qt::SizeVerCursor;
 122                         break;
 123
 124                 case CH_Content:
 125                         shape = buttonDown ? Qt::ClosedHandCursor : Qt::OpenHandCursor;
 126                         break;
 127
 128                 default:
 129                         shape = Qt::ForbiddenCursor;
 130                         break;
 131                 }
 132                 mCropTool->imageView()->viewport()->setCursor(shape);
 133         }
 134 };
 135
 136
 137 CropTool::CropTool(ImageView* view)
 138 : AbstractImageViewTool(view)
 139 , d(new CropToolPrivate) {
 140         d->mCropTool = this;
 141         d->mCropHandleList << CH_Left << CH_Right << CH_Top << CH_Bottom << CH_TopLeft << CH_TopRight << CH_BottomLeft << CH_BottomRight;
 142         d->mMovingHandle = CH_None;
 143         d->mRect.setX(UNINITIALIZED_X);
 144         d->mCropRatio = 0.;
 145 }
 146
 147
 148 CropTool::~CropTool() {
 149         delete d;
 150 }
 151
 152
 153 void CropTool::setCropRatio(double ratio) {
 154         d->mCropRatio = ratio;
 155 }
 156
 157
 158 void CropTool::setRect(const QRect& rect) {
 159         d->mRect = rect;
 160         imageView()->viewport()->update();
 161 }
 162
 163
 164 void CropTool::paint(QPainter* painter) {
 165         if (d->mRect.x() == UNINITIALIZED_X) {
 166                 return;
 167         }
 168         QRect rect = imageView()->mapToViewport(d->mRect);
 169
 170         QRect imageRect = imageView()->rect();
 171
 172         QRegion outerRegion = QRegion(imageRect) - QRegion(rect);
 173         Q_FOREACH(const QRect& outerRect, outerRegion.rects()) {
 174                 painter->fillRect(outerRect, QColor(0, 0, 0, 128));
 175         }
 176
 177         painter->setPen(QPen(Qt::black));
 178
 179         rect.adjust(0, 0, -1, -1);
 180         painter->drawRect(rect);
 181
 182         painter->setBrush(Qt::gray);
 183         painter->setRenderHint(QPainter::Antialiasing);
 184         Q_FOREACH(const CropHandle& handle, d->mCropHandleList) {
 185                 rect = d->handleViewportRect(handle);
 186                 painter->drawEllipse(rect);
 187         }
 188 }
 189
 190
 191 void CropTool::mousePressEvent(QMouseEvent* event) {
 192         if (d->mRect.x() == UNINITIALIZED_X) {
 193                 // Nothing selected, user is creating the crop rect
 194                 QPoint pos = imageView()->mapToImage(event->pos());
 195                 d->mRect = QRect(pos, QSize(0, 0));
 196
 197                 imageView()->viewport()->update();
 198                 rectUpdated(d->mRect);
 199                 return;
 200         }
 201         d->mMovingHandle = d->handleAt(event->pos());
 202         d->updateCursor(d->mMovingHandle, event->buttons() != Qt::NoButton);
 203
 204         if (d->mMovingHandle == CH_Content) {
 205                 d->mLastMouseMovePos = imageView()->mapToImage(event->pos());
 206         }
 207 }
 208
 209
 210 void CropTool::mouseMoveEvent(QMouseEvent* event) {
 211         if (event->buttons() == Qt::NoButton && d->mRect.x() != UNINITIALIZED_X) {
 212                 // Make sure cursor is updated when moving over handles
 213                 CropHandle handle = d->handleAt(event->pos());
 214                 d->updateCursor(handle, false/* buttonDown*/);
 215                 return;
 216         }
 217
 218         QPoint point = imageView()->mapToImage(event->pos());
 219         int posX = point.x(), posY = point.y();
 220
 221         if (d->mRect.x() != UNINITIALIZED_X && d->mRect.size() == QSize(0, 0)) {
 222                 // User is creating rect, thus d->mMovingHandle has not been set yet,
 223                 // figure it out now
 224                 if (posX == d->mRect.x() || posY == d->mRect.y()) {
 225                         // We can't figure the handle yet
 226                         return;
 227                 }
 228                 if (posX < d->mRect.x()) {
 229                         d->mMovingHandle = CH_Left;
 230                 } else {
 231                         d->mMovingHandle = CH_Right;
 232                 }
 233
 234                 if (posY < d->mRect.y()) {
 235                         d->mMovingHandle = CropHandle(d->mMovingHandle | CH_Top);
 236                 } else {
 237                         d->mMovingHandle = CropHandle(d->mMovingHandle | CH_Bottom);
 238                 }
 239
 240                 // Now that we have d->mMovingHandle, we can set the matching cursor shape
 241                 d->updateCursor(d->mMovingHandle, true /*buttonDown*/);
 242         }
 243
 244         if (d->mMovingHandle == CH_None) {
 245                 return;
 246         }
 247
 248         if (d->mMovingHandle & CH_Top) {
 249                 d->mRect.setTop( qMin(posY, d->mRect.bottom()) );
 250         } else if (d->mMovingHandle & CH_Bottom) {
 251                 d->mRect.setBottom( qMax(posY, d->mRect.top()) );
 252         }
 253         if (d->mMovingHandle & CH_Left) {
 254                 d->mRect.setLeft( qMin(posX, d->mRect.right()) );
 255         } else if (d->mMovingHandle & CH_Right) {
 256                 d->mRect.setRight( qMax(posX, d->mRect.left()) );
 257         }
 258
 259         if (d->mCropRatio > 0.) {
 260                 if (d->mMovingHandle == CH_Top || d->mMovingHandle == CH_Bottom) {
 261                         // Top or bottom
 262                         int width = int(d->mRect.height() / d->mCropRatio);
 263                         d->mRect.setWidth(width);
 264                 } else if (d->mMovingHandle == CH_Left || d->mMovingHandle == CH_Right) {
 265                         // Left or right
 266                         int height = int(d->mRect.width() * d->mCropRatio);
 267                         d->mRect.setHeight(height);
 268                 } else if (d->mMovingHandle & CH_Top) {
 269                         // Top left or top right
 270                         int height = int(d->mRect.width() * d->mCropRatio);
 271                         d->mRect.setTop(d->mRect.bottom() - height);
 272                 } else if (d->mMovingHandle & CH_Bottom) {
 273                         // Bottom left or bottom right
 274                         int height = int(d->mRect.width() * d->mCropRatio);
 275                         d->mRect.setHeight(height);
 276                 }
 277         }
 278
 279         if (d->mMovingHandle == CH_Content) {
 280                 QPoint delta = point - d->mLastMouseMovePos;
 281                 d->mRect.adjust(delta.x(), delta.y(), delta.x(), delta.y());
 282                 d->mLastMouseMovePos = imageView()->mapToImage(event->pos());
 283         }
 284
 285         imageView()->viewport()->update();
 286         rectUpdated(d->mRect);
 287 }
 288
 289
 290 void CropTool::mouseReleaseEvent(QMouseEvent* event) {
 291         d->mMovingHandle = CH_None;
 292         d->updateCursor(d->handleAt(event->pos()), false);
 293 }
 294
 295
 296 void CropTool::toolActivated() {
 297         imageView()->viewport()->setCursor(Qt::CrossCursor);
 298 }
 299
 300
 301 } // namespace