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 guint
  41 gtk_aspect_frame_get_type (void)
  42 {
  43   static guint 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         (GtkArgSetFunc) NULL,
  55         (GtkArgGetFunc) NULL,
  56       };
  57
  58       aspect_frame_type = gtk_type_unique (gtk_frame_get_type (), &aspect_frame_info);
  59     }
  60
  61   return aspect_frame_type;
  62 }
  63
  64 static void
  65 gtk_aspect_frame_class_init (GtkAspectFrameClass *class)
  66 {
  67   GtkWidgetClass *widget_class;
  68
  69   widget_class = (GtkWidgetClass*) class;
  70
  71   widget_class->draw = gtk_aspect_frame_draw;
  72   widget_class->expose_event = gtk_aspect_frame_expose;
  73   widget_class->size_allocate = gtk_aspect_frame_size_allocate;
  74 }
  75
  76 static void
  77 gtk_aspect_frame_init (GtkAspectFrame *aspect_frame)
  78 {
  79   aspect_frame->xalign = 0.5;
  80   aspect_frame->yalign = 0.5;
  81   aspect_frame->ratio = 1.0;
  82   aspect_frame->obey_child = 1;
  83   aspect_frame->center_allocation.x = -1;
  84   aspect_frame->center_allocation.y = -1;
  85   aspect_frame->center_allocation.width = 1;
  86   aspect_frame->center_allocation.height = 1;
  87 }
  88
  89 GtkWidget*
  90 gtk_aspect_frame_new (const gchar *label,
  91                       gfloat xalign,
  92                       gfloat yalign,
  93                       gfloat ratio,
  94                       gint   obey_child)
  95 {
  96   GtkAspectFrame *aspect_frame;
  97
  98   aspect_frame = gtk_type_new (gtk_aspect_frame_get_type ());
  99
 100   aspect_frame->xalign = CLAMP (xalign, 0.0, 1.0);
 101   aspect_frame->yalign = CLAMP (yalign, 0.0, 1.0);
 102   aspect_frame->ratio = CLAMP (ratio, MIN_RATIO, MAX_RATIO);
 103   aspect_frame->obey_child = obey_child;
 104
 105   gtk_frame_set_label (GTK_FRAME(aspect_frame), label);
 106
 107   return GTK_WIDGET (aspect_frame);
 108 }
 109
 110 void
 111 gtk_aspect_frame_set (GtkAspectFrame *aspect_frame,
 112                       gfloat        xalign,
 113                       gfloat        yalign,
 114                       gfloat        ratio,
 115                       gint          obey_child)
 116 {
 117   g_return_if_fail (aspect_frame != NULL);
 118   g_return_if_fail (GTK_IS_ASPECT_FRAME (aspect_frame));
 119
 120   xalign = CLAMP (xalign, 0.0, 1.0);
 121   yalign = CLAMP (yalign, 0.0, 1.0);
 122   ratio = CLAMP (ratio, MIN_RATIO, MAX_RATIO);
 123
 124   if ((aspect_frame->xalign != xalign) ||
 125       (aspect_frame->yalign != yalign) ||
 126       (aspect_frame->ratio != ratio) ||
 127       (aspect_frame->obey_child != obey_child))
 128     {
 129       GtkWidget *widget = GTK_WIDGET(aspect_frame);
 130
 131       aspect_frame->xalign = xalign;
 132       aspect_frame->yalign = yalign;
 133       aspect_frame->ratio = ratio;
 134       aspect_frame->obey_child = obey_child;
 135
 136       if (GTK_WIDGET_DRAWABLE(widget))
 137         gdk_window_clear_area (widget->window,
 138                                widget->allocation.x,
 139                                widget->allocation.y,
 140                                widget->allocation.width,
 141                                widget->allocation.height);
 142
 143       gtk_widget_queue_resize (widget);
 144     }
 145 }
 146
 147 static void
 148 gtk_aspect_frame_paint (GtkWidget    *widget,
 149                         GdkRectangle *area)
 150 {
 151   GtkFrame *frame;
 152   gint height_extra;
 153   gint label_area_width;
 154   gint x, y;
 155   GtkAllocation *allocation;
 156
 157   g_return_if_fail (widget != NULL);
 158   g_return_if_fail (GTK_IS_ASPECT_FRAME (widget));
 159   g_return_if_fail (area != NULL);
 160
 161   if (GTK_WIDGET_DRAWABLE (widget))
 162     {
 163       frame = GTK_FRAME (widget);
 164       allocation = &GTK_ASPECT_FRAME(widget)->center_allocation;
 165
 166       height_extra = frame->label_height - widget->style->klass->xthickness;
 167       height_extra = MAX (height_extra, 0);
 168
 169       x = GTK_CONTAINER (frame)->border_width;
 170       y = GTK_CONTAINER (frame)->border_width;
 171
 172       gtk_draw_shadow (widget->style, widget->window,
 173                        GTK_STATE_NORMAL, frame->shadow_type,
 174                        allocation->x + x,
 175                        allocation->y + y + height_extra / 2,
 176                        allocation->width - x * 2,
 177                        allocation->height - y * 2 - height_extra / 2);
 178
 179       if (frame->label)
 180         {
 181           label_area_width = (allocation->width +
 182                               GTK_CONTAINER (frame)->border_width * 2 -
 183                               widget->style->klass->xthickness * 2);
 184
 185           x = ((label_area_width - frame->label_width) * frame->label_xalign +
 186                GTK_CONTAINER (frame)->border_width + widget->style->klass->xthickness);
 187           y = (GTK_CONTAINER (frame)->border_width + widget->style->font->ascent);
 188
 189           gdk_window_clear_area (widget->window,
 190                                  allocation->x + x + 2,
 191                                  allocation->y + GTK_CONTAINER (frame)->border_width,
 192                                  frame->label_width - 4, frame->label_height);
 193           gtk_draw_string (widget->style, widget->window, GTK_WIDGET_STATE (widget),
 194                            allocation->x + x + 3,
 195                            allocation->y + y,
 196                            frame->label);
 197         }
 198     }
 199 }
 200
 201 /* the only modification to the next two routines is to call
 202    gtk_aspect_frame_paint instead of gtk_frame_paint */
 203
 204 static void
 205 gtk_aspect_frame_draw (GtkWidget    *widget,
 206                        GdkRectangle *area)
 207 {
 208   GtkBin *bin;
 209   GdkRectangle child_area;
 210
 211   g_return_if_fail (widget != NULL);
 212   g_return_if_fail (GTK_IS_ASPECT_FRAME (widget));
 213   g_return_if_fail (area != NULL);
 214
 215   if (GTK_WIDGET_DRAWABLE (widget))
 216     {
 217       bin = GTK_BIN (widget);
 218
 219       gtk_aspect_frame_paint (widget, area);
 220
 221       if (bin->child && gtk_widget_intersect (bin->child, area, &child_area))
 222         gtk_widget_draw (bin->child, &child_area);
 223     }
 224 }
 225
 226 static gint
 227 gtk_aspect_frame_expose (GtkWidget      *widget,
 228                          GdkEventExpose *event)
 229 {
 230   GtkBin *bin;
 231   GdkEventExpose child_event;
 232
 233   g_return_val_if_fail (widget != NULL, FALSE);
 234   g_return_val_if_fail (GTK_IS_ASPECT_FRAME (widget), FALSE);
 235   g_return_val_if_fail (event != NULL, FALSE);
 236
 237   if (GTK_WIDGET_DRAWABLE (widget))
 238     {
 239       bin = GTK_BIN (widget);
 240
 241       gtk_aspect_frame_paint (widget, &event->area);
 242
 243       child_event = *event;
 244       if (bin->child &&
 245           GTK_WIDGET_NO_WINDOW (bin->child) &&
 246           gtk_widget_intersect (bin->child, &event->area, &child_event.area))
 247         gtk_widget_event (bin->child, (GdkEvent*) &child_event);
 248     }
 249
 250   return FALSE;
 251 }
 252
 253 static void
 254 gtk_aspect_frame_size_allocate (GtkWidget     *widget,
 255                           GtkAllocation *allocation)
 256 {
 257   GtkFrame *frame;
 258   GtkAspectFrame *aspect_frame;
 259   GtkBin *bin;
 260
 261   GtkAllocation child_allocation;
 262   gint x,y;
 263   gint width,height;
 264   gdouble ratio;
 265
 266   g_return_if_fail (widget != NULL);
 267   g_return_if_fail (GTK_IS_ASPECT_FRAME (widget));
 268   g_return_if_fail (allocation != NULL);
 269
 270   aspect_frame = GTK_ASPECT_FRAME (widget);
 271   frame = GTK_FRAME (widget);
 272   bin = GTK_BIN (widget);
 273
 274   if (GTK_WIDGET_DRAWABLE (widget) &&
 275       ((widget->allocation.x != allocation->x) ||
 276        (widget->allocation.y != allocation->y) ||
 277        (widget->allocation.width != allocation->width) ||
 278        (widget->allocation.height != allocation->height)) &&
 279       (widget->allocation.width != 0) &&
 280       (widget->allocation.height != 0))
 281     gdk_window_clear_area (widget->window,
 282                            widget->allocation.x,
 283                            widget->allocation.y,
 284                            widget->allocation.width,
 285                            widget->allocation.height);
 286
 287   widget->allocation = *allocation;
 288
 289   if (bin->child && GTK_WIDGET_VISIBLE (bin->child))
 290     {
 291       if (aspect_frame->obey_child)
 292         {
 293           if (bin->child->requisition.height != 0)
 294             {
 295               ratio = (gdouble)bin->child->requisition.width /
 296                 bin->child->requisition.height;
 297               if (ratio < MIN_RATIO) ratio = MIN_RATIO;
 298             }
 299           else
 300             if (bin->child->requisition.height != 0)
 301               ratio = MAX_RATIO;
 302           else
 303             ratio = 1.0;
 304         }
 305       else
 306         ratio = aspect_frame->ratio;
 307
 308       x = (GTK_CONTAINER (frame)->border_width +
 309            GTK_WIDGET (frame)->style->klass->xthickness);
 310       width = allocation->width - x * 2;
 311
 312       y = (GTK_CONTAINER (frame)->border_width +
 313                             MAX (frame->label_height, GTK_WIDGET (frame)->style->klass->ythickness));
 314       height = (allocation->height - y -
 315                                  GTK_CONTAINER (frame)->border_width -
 316                                  GTK_WIDGET (frame)->style->klass->ythickness);
 317
 318       /* make sure we don't allocate a negative width or height,
 319        * since that will be cast to a (very big) guint16 */
 320       width = MAX (1, width);
 321       height = MAX (1, height);
 322
 323       if (ratio * height > width)
 324         {
 325           child_allocation.width = width;
 326           child_allocation.height = width/ratio + 0.5;
 327         }
 328       else
 329         {
 330           child_allocation.width = ratio*height + 0.5;
 331           child_allocation.height = height;
 332         }
 333
 334       child_allocation.x = aspect_frame->xalign * (width - child_allocation.width) + allocation->x + x;
 335       child_allocation.y = aspect_frame->yalign * (height - child_allocation.height) + allocation->y + y;
 336
 337       aspect_frame->center_allocation.width = child_allocation.width + 2*x;
 338       aspect_frame->center_allocation.x = child_allocation.x - x;
 339       aspect_frame->center_allocation.height = child_allocation.height + y +
 340                                  GTK_CONTAINER (frame)->border_width +
 341                                  GTK_WIDGET (frame)->style->klass->ythickness;
 342       aspect_frame->center_allocation.y = child_allocation.y - y;
 343
 344       gtk_widget_size_allocate (bin->child, &child_allocation);
 345     }
 346 }