Pileus Git - ~andy/gtk/blob - gtk/gtkaspectframe.c

   1 /* GTK - The GIMP Toolkit
   2  * Copyright (C) 1995-1997 Peter Mattis, Spencer Kimball and Josh MacDonald
   3  *
   4  * GtkAspectFrame: Ensure that the child window has a specified aspect ratio
   5  *    or, if obey_child, has the same aspect ratio as its requested size
   6  *
   7  *     Copyright Owen Taylor                          4/9/97
   8  *
   9  * This library is free software; you can redistribute it and/or
  10  * modify it under the terms of the GNU Library General Public
  11  * License as published by the Free Software Foundation; either
  12  * version 2 of the License, or (at your option) any later version.
  13  *
  14  * This library is distributed in the hope that it will be useful,
  15  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  16  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  17  * Library General Public License for more details.
  18  *
  19  * You should have received a copy of the GNU Library General Public
  20  * License along with this library; if not, write to the
  21  * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
  22  * Boston, MA 02111-1307, USA.
  23  */
  24 #include "gtkaspectframe.h"
  25
  26 static void gtk_aspect_frame_class_init    (GtkAspectFrameClass *klass);
  27 static void gtk_aspect_frame_init          (GtkAspectFrame      *aspect_frame);
  28 static void gtk_aspect_frame_draw          (GtkWidget      *widget,
  29                                             GdkRectangle   *area);
  30 static void gtk_aspect_frame_paint         (GtkWidget      *widget,
  31                                             GdkRectangle   *area);
  32 static gint gtk_aspect_frame_expose        (GtkWidget      *widget,
  33                                             GdkEventExpose *event);
  34 static void gtk_aspect_frame_size_allocate (GtkWidget         *widget,
  35                                             GtkAllocation     *allocation);
  36
  37 #define MAX_RATIO 10000.0
  38 #define MIN_RATIO 0.0001
  39
  40 GtkType
  41 gtk_aspect_frame_get_type (void)
  42 {
  43   static GtkType aspect_frame_type = 0;
  44
  45   if (!aspect_frame_type)
  46     {
  47       GtkTypeInfo aspect_frame_info =
  48       {
  49         "GtkAspectFrame",
  50         sizeof (GtkAspectFrame),
  51         sizeof (GtkAspectFrameClass),
  52         (GtkClassInitFunc) gtk_aspect_frame_class_init,
  53         (GtkObjectInitFunc) gtk_aspect_frame_init,
  54         /* reversed_1 */ NULL,
  55         /* reversed_2 */ NULL,
  56         (GtkClassInitFunc) NULL,
  57       };
  58
  59       aspect_frame_type = gtk_type_unique (gtk_frame_get_type (), &aspect_frame_info);
  60     }
  61
  62   return aspect_frame_type;
  63 }
  64
  65 static void
  66 gtk_aspect_frame_class_init (GtkAspectFrameClass *class)
  67 {
  68   GtkWidgetClass *widget_class;
  69
  70   widget_class = (GtkWidgetClass*) class;
  71
  72   widget_class->draw = gtk_aspect_frame_draw;
  73   widget_class->expose_event = gtk_aspect_frame_expose;
  74   widget_class->size_allocate = gtk_aspect_frame_size_allocate;
  75 }
  76
  77 static void
  78 gtk_aspect_frame_init (GtkAspectFrame *aspect_frame)
  79 {
  80   aspect_frame->xalign = 0.5;
  81   aspect_frame->yalign = 0.5;
  82   aspect_frame->ratio = 1.0;
  83   aspect_frame->obey_child = 1;
  84   aspect_frame->center_allocation.x = -1;
  85   aspect_frame->center_allocation.y = -1;
  86   aspect_frame->center_allocation.width = 1;
  87   aspect_frame->center_allocation.height = 1;
  88 }
  89
  90 GtkWidget*
  91 gtk_aspect_frame_new (const gchar *label,
  92                       gfloat xalign,
  93                       gfloat yalign,
  94                       gfloat ratio,
  95                       gint   obey_child)
  96 {
  97   GtkAspectFrame *aspect_frame;
  98
  99   aspect_frame = gtk_type_new (gtk_aspect_frame_get_type ());
 100
 101   aspect_frame->xalign = CLAMP (xalign, 0.0, 1.0);
 102   aspect_frame->yalign = CLAMP (yalign, 0.0, 1.0);
 103   aspect_frame->ratio = CLAMP (ratio, MIN_RATIO, MAX_RATIO);
 104   aspect_frame->obey_child = obey_child;
 105
 106   gtk_frame_set_label (GTK_FRAME(aspect_frame), label);
 107
 108   return GTK_WIDGET (aspect_frame);
 109 }
 110
 111 void
 112 gtk_aspect_frame_set (GtkAspectFrame *aspect_frame,
 113                       gfloat        xalign,
 114                       gfloat        yalign,
 115                       gfloat        ratio,
 116                       gint          obey_child)
 117 {
 118   g_return_if_fail (aspect_frame != NULL);
 119   g_return_if_fail (GTK_IS_ASPECT_FRAME (aspect_frame));
 120
 121   xalign = CLAMP (xalign, 0.0, 1.0);
 122   yalign = CLAMP (yalign, 0.0, 1.0);
 123   ratio = CLAMP (ratio, MIN_RATIO, MAX_RATIO);
 124
 125   if ((aspect_frame->xalign != xalign) ||
 126       (aspect_frame->yalign != yalign) ||
 127       (aspect_frame->ratio != ratio) ||
 128       (aspect_frame->obey_child != obey_child))
 129     {
 130       GtkWidget *widget = GTK_WIDGET(aspect_frame);
 131
 132       aspect_frame->xalign = xalign;
 133       aspect_frame->yalign = yalign;
 134       aspect_frame->ratio = ratio;
 135       aspect_frame->obey_child = obey_child;
 136
 137       if (GTK_WIDGET_DRAWABLE(widget))
 138         gdk_window_clear_area (widget->window,
 139                                widget->allocation.x,
 140                                widget->allocation.y,
 141                                widget->allocation.width,
 142                                widget->allocation.height);
 143
 144       gtk_widget_queue_resize (widget);
 145     }
 146 }
 147
 148 static void
 149 gtk_aspect_frame_paint (GtkWidget    *widget,
 150                         GdkRectangle *area)
 151 {
 152   GtkFrame *frame;
 153   gint height_extra;
 154   gint label_area_width;
 155   gint x, y;
 156   GtkAllocation *allocation;
 157
 158   g_return_if_fail (widget != NULL);
 159   g_return_if_fail (GTK_IS_ASPECT_FRAME (widget));
 160   g_return_if_fail (area != NULL);
 161
 162   if (GTK_WIDGET_DRAWABLE (widget))
 163     {
 164       frame = GTK_FRAME (widget);
 165       allocation = &GTK_ASPECT_FRAME(widget)->center_allocation;
 166
 167       height_extra = frame->label_height - widget->style->klass->xthickness;
 168       height_extra = MAX (height_extra, 0);
 169
 170       x = GTK_CONTAINER (frame)->border_width;
 171       y = GTK_CONTAINER (frame)->border_width;
 172
 173       gtk_draw_shadow (widget->style, widget->window,
 174                        GTK_STATE_NORMAL, frame->shadow_type,
 175                        allocation->x + x,
 176                        allocation->y + y + height_extra / 2,
 177                        allocation->width - x * 2,
 178                        allocation->height - y * 2 - height_extra / 2);
 179
 180       if (frame->label)
 181         {
 182           label_area_width = (allocation->width +
 183                               GTK_CONTAINER (frame)->border_width * 2 -
 184                               widget->style->klass->xthickness * 2);
 185
 186           x = ((label_area_width - frame->label_width) * frame->label_xalign +
 187                GTK_CONTAINER (frame)->border_width + widget->style->klass->xthickness);
 188           y = (GTK_CONTAINER (frame)->border_width + widget->style->font->ascent);
 189
 190           gdk_window_clear_area (widget->window,
 191                                  allocation->x + x + 2,
 192                                  allocation->y + GTK_CONTAINER (frame)->border_width,
 193                                  frame->label_width - 4, frame->label_height);
 194           gtk_draw_string (widget->style, widget->window, GTK_WIDGET_STATE (widget),
 195                            allocation->x + x + 3,
 196                            allocation->y + y,
 197                            frame->label);
 198         }
 199     }
 200 }
 201
 202 /* the only modification to the next two routines is to call
 203    gtk_aspect_frame_paint instead of gtk_frame_paint */
 204
 205 static void
 206 gtk_aspect_frame_draw (GtkWidget    *widget,
 207                        GdkRectangle *area)
 208 {
 209   GtkBin *bin;
 210   GdkRectangle child_area;
 211
 212   g_return_if_fail (widget != NULL);
 213   g_return_if_fail (GTK_IS_ASPECT_FRAME (widget));
 214   g_return_if_fail (area != NULL);
 215
 216   if (GTK_WIDGET_DRAWABLE (widget))
 217     {
 218       bin = GTK_BIN (widget);
 219
 220       gtk_aspect_frame_paint (widget, area);
 221
 222       if (bin->child && gtk_widget_intersect (bin->child, area, &child_area))
 223         gtk_widget_draw (bin->child, &child_area);
 224     }
 225 }
 226
 227 static gint
 228 gtk_aspect_frame_expose (GtkWidget      *widget,
 229                          GdkEventExpose *event)
 230 {
 231   GtkBin *bin;
 232   GdkEventExpose child_event;
 233
 234   g_return_val_if_fail (widget != NULL, FALSE);
 235   g_return_val_if_fail (GTK_IS_ASPECT_FRAME (widget), FALSE);
 236   g_return_val_if_fail (event != NULL, FALSE);
 237
 238   if (GTK_WIDGET_DRAWABLE (widget))
 239     {
 240       bin = GTK_BIN (widget);
 241
 242       gtk_aspect_frame_paint (widget, &event->area);
 243
 244       child_event = *event;
 245       if (bin->child &&
 246           GTK_WIDGET_NO_WINDOW (bin->child) &&
 247           gtk_widget_intersect (bin->child, &event->area, &child_event.area))
 248         gtk_widget_event (bin->child, (GdkEvent*) &child_event);
 249     }
 250
 251   return FALSE;
 252 }
 253
 254 static void
 255 gtk_aspect_frame_size_allocate (GtkWidget     *widget,
 256                           GtkAllocation *allocation)
 257 {
 258   GtkFrame *frame;
 259   GtkAspectFrame *aspect_frame;
 260   GtkBin *bin;
 261
 262   GtkAllocation child_allocation;
 263   gint x,y;
 264   gint width,height;
 265   gdouble ratio;
 266
 267   g_return_if_fail (widget != NULL);
 268   g_return_if_fail (GTK_IS_ASPECT_FRAME (widget));
 269   g_return_if_fail (allocation != NULL);
 270
 271   aspect_frame = GTK_ASPECT_FRAME (widget);
 272   frame = GTK_FRAME (widget);
 273   bin = GTK_BIN (widget);
 274
 275   if (GTK_WIDGET_DRAWABLE (widget) &&
 276       ((widget->allocation.x != allocation->x) ||
 277        (widget->allocation.y != allocation->y) ||
 278        (widget->allocation.width != allocation->width) ||
 279        (widget->allocation.height != allocation->height)) &&
 280       (widget->allocation.width != 0) &&
 281       (widget->allocation.height != 0))
 282     gdk_window_clear_area (widget->window,
 283                            widget->allocation.x,
 284                            widget->allocation.y,
 285                            widget->allocation.width,
 286                            widget->allocation.height);
 287
 288   widget->allocation = *allocation;
 289
 290   if (bin->child && GTK_WIDGET_VISIBLE (bin->child))
 291     {
 292       if (aspect_frame->obey_child)
 293         {
 294           if (bin->child->requisition.height != 0)
 295             {
 296               ratio = (gdouble)bin->child->requisition.width /
 297                 bin->child->requisition.height;
 298               if (ratio < MIN_RATIO) ratio = MIN_RATIO;
 299             }
 300           else
 301             if (bin->child->requisition.height != 0)
 302               ratio = MAX_RATIO;
 303           else
 304             ratio = 1.0;
 305         }
 306       else
 307         ratio = aspect_frame->ratio;
 308
 309       x = (GTK_CONTAINER (frame)->border_width +
 310            GTK_WIDGET (frame)->style->klass->xthickness);
 311       width = allocation->width - x * 2;
 312
 313       y = (GTK_CONTAINER (frame)->border_width +
 314                             MAX (frame->label_height, GTK_WIDGET (frame)->style->klass->ythickness));
 315       height = (allocation->height - y -
 316                                  GTK_CONTAINER (frame)->border_width -
 317                                  GTK_WIDGET (frame)->style->klass->ythickness);
 318
 319       /* make sure we don't allocate a negative width or height,
 320        * since that will be cast to a (very big) guint16 */
 321       width = MAX (1, width);
 322       height = MAX (1, height);
 323
 324       if (ratio * height > width)
 325         {
 326           child_allocation.width = width;
 327           child_allocation.height = width/ratio + 0.5;
 328         }
 329       else
 330         {
 331           child_allocation.width = ratio*height + 0.5;
 332           child_allocation.height = height;
 333         }
 334
 335       child_allocation.x = aspect_frame->xalign * (width - child_allocation.width) + allocation->x + x;
 336       child_allocation.y = aspect_frame->yalign * (height - child_allocation.height) + allocation->y + y;
 337
 338       aspect_frame->center_allocation.width = child_allocation.width + 2*x;
 339       aspect_frame->center_allocation.x = child_allocation.x - x;
 340       aspect_frame->center_allocation.height = child_allocation.height + y +
 341                                  GTK_CONTAINER (frame)->border_width +
 342                                  GTK_WIDGET (frame)->style->klass->ythickness;
 343       aspect_frame->center_allocation.y = child_allocation.y - y;
 344
 345       gtk_widget_size_allocate (bin->child, &child_allocation);
 346     }
 347 }