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 Free
  21  * Software Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
  22  */
  23 #include "gtkaspectframe.h"
  24
  25 static void gtk_aspect_frame_class_init    (GtkAspectFrameClass *klass);
  26 static void gtk_aspect_frame_init          (GtkAspectFrame      *aspect_frame);
  27 static void gtk_aspect_frame_draw          (GtkWidget      *widget,
  28                                             GdkRectangle   *area);
  29 static void gtk_aspect_frame_paint         (GtkWidget      *widget,
  30                                             GdkRectangle   *area);
  31 static gint gtk_aspect_frame_expose        (GtkWidget      *widget,
  32                                             GdkEventExpose *event);
  33 static void gtk_aspect_frame_size_allocate (GtkWidget         *widget,
  34                                             GtkAllocation     *allocation);
  35
  36 #define MAX_RATIO 10000.0
  37 #define MIN_RATIO 0.0001
  38
  39 guint
  40 gtk_aspect_frame_get_type ()
  41 {
  42   static guint aspect_frame_type = 0;
  43
  44   if (!aspect_frame_type)
  45     {
  46       GtkTypeInfo aspect_frame_info =
  47       {
  48         "GtkAspectFrame",
  49         sizeof (GtkAspectFrame),
  50         sizeof (GtkAspectFrameClass),
  51         (GtkClassInitFunc) gtk_aspect_frame_class_init,
  52         (GtkObjectInitFunc) gtk_aspect_frame_init,
  53         (GtkArgFunc) NULL,
  54       };
  55
  56       aspect_frame_type = gtk_type_unique (gtk_frame_get_type (), &aspect_frame_info);
  57     }
  58
  59   return aspect_frame_type;
  60 }
  61
  62 static void
  63 gtk_aspect_frame_class_init (GtkAspectFrameClass *class)
  64 {
  65   GtkWidgetClass *widget_class;
  66
  67   widget_class = (GtkWidgetClass*) class;
  68
  69   widget_class->draw = gtk_aspect_frame_draw;
  70   widget_class->expose_event = gtk_aspect_frame_expose;
  71   widget_class->size_allocate = gtk_aspect_frame_size_allocate;
  72 }
  73
  74 static void
  75 gtk_aspect_frame_init (GtkAspectFrame *aspect_frame)
  76 {
  77   aspect_frame->xalign = 0.5;
  78   aspect_frame->yalign = 0.5;
  79   aspect_frame->ratio = 1.0;
  80   aspect_frame->obey_child = 1;
  81   aspect_frame->center_allocation.x = -1;
  82   aspect_frame->center_allocation.y = -1;
  83   aspect_frame->center_allocation.width = 1;
  84   aspect_frame->center_allocation.height = 1;
  85 }
  86
  87 GtkWidget*
  88 gtk_aspect_frame_new (const gchar *label,
  89                       gfloat xalign,
  90                       gfloat yalign,
  91                       gfloat ratio,
  92                       gint   obey_child)
  93 {
  94   GtkAspectFrame *aspect_frame;
  95
  96   aspect_frame = gtk_type_new (gtk_aspect_frame_get_type ());
  97
  98   aspect_frame->xalign = CLAMP (xalign, 0.0, 1.0);
  99   aspect_frame->yalign = CLAMP (yalign, 0.0, 1.0);
 100   aspect_frame->ratio = CLAMP (ratio, MIN_RATIO, MAX_RATIO);
 101   aspect_frame->obey_child = obey_child;
 102
 103   gtk_frame_set_label (GTK_FRAME(aspect_frame), label);
 104
 105   return GTK_WIDGET (aspect_frame);
 106 }
 107
 108 void
 109 gtk_aspect_frame_set (GtkAspectFrame *aspect_frame,
 110                       gfloat        xalign,
 111                       gfloat        yalign,
 112                       gfloat        ratio,
 113                       gint          obey_child)
 114 {
 115   g_return_if_fail (aspect_frame != NULL);
 116   g_return_if_fail (GTK_IS_ASPECT_FRAME (aspect_frame));
 117
 118   xalign = CLAMP (xalign, 0.0, 1.0);
 119   yalign = CLAMP (yalign, 0.0, 1.0);
 120   ratio = CLAMP (ratio, MIN_RATIO, MAX_RATIO);
 121
 122   if ((aspect_frame->xalign != xalign) ||
 123       (aspect_frame->yalign != yalign) ||
 124       (aspect_frame->ratio != ratio) ||
 125       (aspect_frame->obey_child != obey_child))
 126     {
 127       GtkWidget * this = GTK_WIDGET(aspect_frame);
 128
 129       aspect_frame->xalign = xalign;
 130       aspect_frame->yalign = yalign;
 131       aspect_frame->ratio = ratio;
 132       aspect_frame->obey_child = obey_child;
 133
 134       if (GTK_WIDGET_MAPPED(this))
 135           gdk_window_clear_area (this->window,
 136                                  this->allocation.x,
 137                                  this->allocation.y,
 138                                  this->allocation.width,
 139                                  this->allocation.height);
 140
 141       gtk_widget_size_allocate (this, &this->allocation);
 142       gtk_widget_queue_draw (this);
 143     }
 144 }
 145
 146 static void
 147 gtk_aspect_frame_paint (GtkWidget    *widget,
 148                         GdkRectangle *area)
 149 {
 150   GtkFrame *frame;
 151   GtkStateType state;
 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       state = widget->state;
 167       if (!GTK_WIDGET_IS_SENSITIVE (widget))
 168         state = GTK_STATE_INSENSITIVE;
 169
 170       height_extra = frame->label_height - widget->style->klass->xthickness;
 171       height_extra = MAX (height_extra, 0);
 172
 173       x = GTK_CONTAINER (frame)->border_width;
 174       y = GTK_CONTAINER (frame)->border_width;
 175
 176       gtk_draw_shadow (widget->style, widget->window,
 177                        GTK_STATE_NORMAL, frame->shadow_type,
 178                        allocation->x + x,
 179                        allocation->y + y + height_extra / 2,
 180                        allocation->width - x * 2,
 181                        allocation->height - y * 2 - height_extra / 2);
 182
 183       if (frame->label)
 184         {
 185           label_area_width = (allocation->width +
 186                               GTK_CONTAINER (frame)->border_width * 2 -
 187                               widget->style->klass->xthickness * 2);
 188
 189           x = ((label_area_width - frame->label_width) * frame->label_xalign +
 190                GTK_CONTAINER (frame)->border_width + widget->style->klass->xthickness);
 191           y = (GTK_CONTAINER (frame)->border_width + widget->style->font->ascent);
 192
 193           gdk_window_clear_area (widget->window,
 194                                  allocation->x + x + 2,
 195                                  allocation->y + GTK_CONTAINER (frame)->border_width,
 196                                  frame->label_width - 4, frame->label_height);
 197           gtk_draw_string (widget->style, widget->window, state,
 198                            allocation->x + x + 3,
 199                            allocation->y + y,
 200                            frame->label);
 201         }
 202     }
 203 }
 204
 205 /* the only modification to the next two routines is to call
 206    gtk_aspect_frame_paint instead of gtk_frame_paint */
 207
 208 static void
 209 gtk_aspect_frame_draw (GtkWidget    *widget,
 210                        GdkRectangle *area)
 211 {
 212   GtkBin *bin;
 213   GdkRectangle child_area;
 214
 215   g_return_if_fail (widget != NULL);
 216   g_return_if_fail (GTK_IS_ASPECT_FRAME (widget));
 217   g_return_if_fail (area != NULL);
 218
 219   if (GTK_WIDGET_DRAWABLE (widget))
 220     {
 221       bin = GTK_BIN (widget);
 222
 223       gtk_aspect_frame_paint (widget, area);
 224
 225       if (bin->child && gtk_widget_intersect (bin->child, area, &child_area))
 226         gtk_widget_draw (bin->child, &child_area);
 227     }
 228 }
 229
 230 static gint
 231 gtk_aspect_frame_expose (GtkWidget      *widget,
 232                          GdkEventExpose *event)
 233 {
 234   GtkBin *bin;
 235   GdkEventExpose child_event;
 236
 237   g_return_val_if_fail (widget != NULL, FALSE);
 238   g_return_val_if_fail (GTK_IS_ASPECT_FRAME (widget), FALSE);
 239   g_return_val_if_fail (event != NULL, FALSE);
 240
 241   if (GTK_WIDGET_DRAWABLE (widget))
 242     {
 243       bin = GTK_BIN (widget);
 244
 245       gtk_aspect_frame_paint (widget, &event->area);
 246
 247       child_event = *event;
 248       if (bin->child &&
 249           GTK_WIDGET_NO_WINDOW (bin->child) &&
 250           gtk_widget_intersect (bin->child, &event->area, &child_event.area))
 251         gtk_widget_event (bin->child, (GdkEvent*) &child_event);
 252     }
 253
 254   return FALSE;
 255 }
 256
 257 static void
 258 gtk_aspect_frame_size_allocate (GtkWidget     *widget,
 259                           GtkAllocation *allocation)
 260 {
 261   GtkFrame *frame;
 262   GtkAspectFrame *aspect_frame;
 263   GtkBin *bin;
 264
 265   GtkAllocation child_allocation;
 266   gint x,y;
 267   gint width,height;
 268   gdouble ratio;
 269
 270   g_return_if_fail (widget != NULL);
 271   g_return_if_fail (GTK_IS_ASPECT_FRAME (widget));
 272   g_return_if_fail (allocation != NULL);
 273
 274   aspect_frame = GTK_ASPECT_FRAME (widget);
 275   frame = GTK_FRAME (widget);
 276   bin = GTK_BIN (widget);
 277
 278   if (GTK_WIDGET_MAPPED (widget) &&
 279       ((widget->allocation.x != allocation->x) ||
 280        (widget->allocation.y != allocation->y) ||
 281        (widget->allocation.width != allocation->width) ||
 282        (widget->allocation.height != allocation->height)) &&
 283       (widget->allocation.width != 0) &&
 284       (widget->allocation.height != 0))
 285     gdk_window_clear_area (widget->window,
 286                            widget->allocation.x,
 287                            widget->allocation.y,
 288                            widget->allocation.width,
 289                            widget->allocation.height);
 290
 291   widget->allocation = *allocation;
 292
 293   if (bin->child && GTK_WIDGET_VISIBLE (bin->child))
 294     {
 295       if (aspect_frame->obey_child)
 296         {
 297           if (bin->child->requisition.height != 0)
 298             {
 299               ratio = (gdouble)bin->child->requisition.width /
 300                 bin->child->requisition.height;
 301               if (ratio < MIN_RATIO) ratio = MIN_RATIO;
 302             }
 303           else
 304             if (bin->child->requisition.height != 0)
 305               ratio = MAX_RATIO;
 306           else
 307             ratio = 1.0;
 308         }
 309       else
 310         ratio = aspect_frame->ratio;
 311
 312       x = (GTK_CONTAINER (frame)->border_width +
 313            GTK_WIDGET (frame)->style->klass->xthickness);
 314       width = allocation->width - x * 2;
 315
 316       y = (GTK_CONTAINER (frame)->border_width +
 317                             MAX (frame->label_height, GTK_WIDGET (frame)->style->klass->ythickness));
 318       height = (allocation->height - y -
 319                                  GTK_CONTAINER (frame)->border_width -
 320                                  GTK_WIDGET (frame)->style->klass->ythickness);
 321
 322       if (height > width / ratio)
 323         {
 324           child_allocation.width = width;
 325           child_allocation.height = width/ratio + 0.5;
 326         }
 327       else if (width > height * ratio)
 328         {
 329           child_allocation.width = ratio * height + 0.5;
 330           child_allocation.height = height;
 331         }
 332
 333       child_allocation.x = aspect_frame->xalign * (width - child_allocation.width) + allocation->x + x;
 334       child_allocation.y = aspect_frame->yalign * (height - child_allocation.height) + allocation->y + y;
 335
 336       aspect_frame->center_allocation.width = child_allocation.width + 2*x;
 337       aspect_frame->center_allocation.x = child_allocation.x - x;
 338       aspect_frame->center_allocation.height = child_allocation.height + y +
 339                                  GTK_CONTAINER (frame)->border_width +
 340                                  GTK_WIDGET (frame)->style->klass->ythickness;
 341       aspect_frame->center_allocation.y = child_allocation.y - y;
 342
 343       gtk_widget_size_allocate (bin->child, &child_allocation);
 344     }
 345 }