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       static const 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         /* reserved_1 */ NULL,
  55         /* reserved_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         gtk_widget_queue_clear (widget);
 139
 140       gtk_widget_queue_resize (widget);
 141     }
 142 }
 143
 144 static void
 145 gtk_aspect_frame_paint (GtkWidget    *widget,
 146                         GdkRectangle *area)
 147 {
 148   GtkFrame *frame;
 149   gint height_extra;
 150   gint label_area_width;
 151   gint x, y, x2, y2;
 152   GtkAllocation *allocation;
 153
 154   g_return_if_fail (widget != NULL);
 155   g_return_if_fail (GTK_IS_ASPECT_FRAME (widget));
 156   g_return_if_fail (area != NULL);
 157
 158   if (GTK_WIDGET_DRAWABLE (widget))
 159     {
 160       frame = GTK_FRAME (widget);
 161       allocation = &GTK_ASPECT_FRAME(widget)->center_allocation;
 162
 163       height_extra = frame->label_height - widget->style->klass->xthickness;
 164       height_extra = MAX (height_extra, 0);
 165
 166       x = GTK_CONTAINER (frame)->border_width;
 167       y = GTK_CONTAINER (frame)->border_width;
 168
 169       if (frame->label)
 170         {
 171           label_area_width = (allocation->width +
 172                               GTK_CONTAINER (frame)->border_width * 2 -
 173                               widget->style->klass->xthickness * 2);
 174
 175           x2 = ((label_area_width - frame->label_width) * frame->label_xalign +
 176                 GTK_CONTAINER (frame)->border_width + widget->style->klass->xthickness);
 177           y2 = (GTK_CONTAINER (frame)->border_width + widget->style->font->ascent);
 178
 179           gtk_paint_shadow_gap (widget->style, widget->window,
 180                                 GTK_STATE_NORMAL, frame->shadow_type,
 181                                 area, widget, "frame",
 182                                 allocation->x + x,
 183                                 allocation->y + y + height_extra / 2,
 184                                 allocation->width - x * 2,
 185                                 allocation->height - y * 2 - height_extra / 2,
 186                                 GTK_POS_TOP,
 187                                 x2 + 2 - x, frame->label_width - 4);
 188
 189           gtk_paint_string (widget->style, widget->window, GTK_WIDGET_STATE (widget),
 190                             area, widget, "frame",
 191                             allocation->x + x2 + 3,
 192                             allocation->y + y2,
 193                             frame->label);
 194         }
 195       else
 196         gtk_paint_shadow (widget->style, widget->window,
 197                           GTK_STATE_NORMAL, frame->shadow_type,
 198                           area, widget, "frame",
 199                           allocation->x + x,
 200                           allocation->y + y + height_extra / 2,
 201                           allocation->width - x * 2,
 202                           allocation->height - y * 2 - height_extra / 2);
 203     }
 204 }
 205
 206 /* the only modification to the next two routines is to call
 207    gtk_aspect_frame_paint instead of gtk_frame_paint */
 208
 209 static void
 210 gtk_aspect_frame_draw (GtkWidget    *widget,
 211                        GdkRectangle *area)
 212 {
 213   GtkBin *bin;
 214   GdkRectangle child_area;
 215
 216   g_return_if_fail (widget != NULL);
 217   g_return_if_fail (GTK_IS_ASPECT_FRAME (widget));
 218   g_return_if_fail (area != NULL);
 219
 220   if (GTK_WIDGET_DRAWABLE (widget))
 221     {
 222       bin = GTK_BIN (widget);
 223
 224       gtk_aspect_frame_paint (widget, area);
 225
 226       if (bin->child && gtk_widget_intersect (bin->child, area, &child_area))
 227         gtk_widget_draw (bin->child, &child_area);
 228     }
 229 }
 230
 231 static gint
 232 gtk_aspect_frame_expose (GtkWidget      *widget,
 233                          GdkEventExpose *event)
 234 {
 235   GtkBin *bin;
 236   GdkEventExpose child_event;
 237
 238   g_return_val_if_fail (widget != NULL, FALSE);
 239   g_return_val_if_fail (GTK_IS_ASPECT_FRAME (widget), FALSE);
 240   g_return_val_if_fail (event != NULL, FALSE);
 241
 242   if (GTK_WIDGET_DRAWABLE (widget))
 243     {
 244       bin = GTK_BIN (widget);
 245
 246       gtk_aspect_frame_paint (widget, &event->area);
 247
 248       child_event = *event;
 249       if (bin->child &&
 250           GTK_WIDGET_NO_WINDOW (bin->child) &&
 251           gtk_widget_intersect (bin->child, &event->area, &child_event.area))
 252         gtk_widget_event (bin->child, (GdkEvent*) &child_event);
 253     }
 254
 255   return FALSE;
 256 }
 257
 258 static void
 259 gtk_aspect_frame_size_allocate (GtkWidget     *widget,
 260                           GtkAllocation *allocation)
 261 {
 262   GtkFrame *frame;
 263   GtkAspectFrame *aspect_frame;
 264   GtkBin *bin;
 265
 266   GtkAllocation child_allocation;
 267   gint x,y;
 268   gint width,height;
 269   gdouble ratio;
 270
 271   g_return_if_fail (widget != NULL);
 272   g_return_if_fail (GTK_IS_ASPECT_FRAME (widget));
 273   g_return_if_fail (allocation != NULL);
 274
 275   aspect_frame = GTK_ASPECT_FRAME (widget);
 276   frame = GTK_FRAME (widget);
 277   bin = GTK_BIN (widget);
 278
 279   if (GTK_WIDGET_DRAWABLE (widget) &&
 280       ((widget->allocation.x != allocation->x) ||
 281        (widget->allocation.y != allocation->y) ||
 282        (widget->allocation.width != allocation->width) ||
 283        (widget->allocation.height != allocation->height)) &&
 284       (widget->allocation.width != 0) &&
 285       (widget->allocation.height != 0))
 286     gdk_window_clear_area (widget->window,
 287                            widget->allocation.x,
 288                            widget->allocation.y,
 289                            widget->allocation.width,
 290                            widget->allocation.height);
 291
 292   widget->allocation = *allocation;
 293
 294   if (bin->child && GTK_WIDGET_VISIBLE (bin->child))
 295     {
 296       if (aspect_frame->obey_child)
 297         {
 298           GtkRequisition child_requisition;
 299
 300           gtk_widget_get_child_requisition (bin->child, &child_requisition);
 301           if (child_requisition.height != 0)
 302             {
 303               ratio = (gdouble)child_requisition.width /
 304                                child_requisition.height;
 305               if (ratio < MIN_RATIO) ratio = MIN_RATIO;
 306             }
 307           else if (child_requisition.width != 0)
 308             ratio = MAX_RATIO;
 309           else
 310             ratio = 1.0;
 311         }
 312       else
 313         ratio = aspect_frame->ratio;
 314
 315       x = (GTK_CONTAINER (frame)->border_width +
 316            GTK_WIDGET (frame)->style->klass->xthickness);
 317       width = allocation->width - x * 2;
 318
 319       y = (GTK_CONTAINER (frame)->border_width +
 320                             MAX (frame->label_height, GTK_WIDGET (frame)->style->klass->ythickness));
 321       height = (allocation->height - y -
 322                                  GTK_CONTAINER (frame)->border_width -
 323                                  GTK_WIDGET (frame)->style->klass->ythickness);
 324
 325       /* make sure we don't allocate a negative width or height,
 326        * since that will be cast to a (very big) guint16 */
 327       width = MAX (1, width);
 328       height = MAX (1, height);
 329
 330       if (ratio * height > width)
 331         {
 332           child_allocation.width = width;
 333           child_allocation.height = width/ratio + 0.5;
 334         }
 335       else
 336         {
 337           child_allocation.width = ratio*height + 0.5;
 338           child_allocation.height = height;
 339         }
 340
 341       child_allocation.x = aspect_frame->xalign * (width - child_allocation.width) + allocation->x + x;
 342       child_allocation.y = aspect_frame->yalign * (height - child_allocation.height) + allocation->y + y;
 343
 344       aspect_frame->center_allocation.width = child_allocation.width + 2*x;
 345       aspect_frame->center_allocation.x = child_allocation.x - x;
 346       aspect_frame->center_allocation.height = child_allocation.height + y +
 347                                  GTK_CONTAINER (frame)->border_width +
 348                                  GTK_WIDGET (frame)->style->klass->ythickness;
 349       aspect_frame->center_allocation.y = child_allocation.y - y;
 350
 351       gtk_widget_size_allocate (bin->child, &child_allocation);
 352     }
 353 }