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

   1 /* GTK - The GIMP Toolkit
   2  * Copyright (C) 1995-1997 Peter Mattis, Spencer Kimball and Josh MacDonald
   3  *
   4  * This library is free software; you can redistribute it and/or
   5  * modify it under the terms of the GNU Lesser General Public
   6  * License as published by the Free Software Foundation; either
   7  * version 2 of the License, or (at your option) any later version.
   8  *
   9  * This library is distributed in the hope that it will be useful,
  10  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  11  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  12  * Lesser General Public License for more details.
  13  *
  14  * You should have received a copy of the GNU Lesser General Public
  15  * License along with this library; if not, write to the
  16  * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
  17  * Boston, MA 02111-1307, USA.
  18  */
  19
  20 /*
  21  * Modified by the GTK+ Team and others 1997-2001.  See the AUTHORS
  22  * file for a list of people on the GTK+ Team.  See the ChangeLog
  23  * files for a list of changes.  These files are distributed with
  24  * GTK+ at ftp://ftp.gtk.org/pub/gtk/.
  25  */
  26
  27 /**
  28  * SECTION:gtkarrow
  29  * @Short_description: Displays an arrow
  30  * @Title: GtkArrow
  31  * @See_also: gtk_render_arrow()
  32  *
  33  * GtkArrow should be used to draw simple arrows that need to point in
  34  * one of the four cardinal directions (up, down, left, or right).  The
  35  * style of the arrow can be one of shadow in, shadow out, etched in, or
  36  * etched out.  Note that these directions and style types may be
  37  * ammended in versions of GTK+ to come.
  38  *
  39  * GtkArrow will fill any space alloted to it, but since it is inherited
  40  * from #GtkMisc, it can be padded and/or aligned, to fill exactly the
  41  * space the programmer desires.
  42  *
  43  * Arrows are created with a call to gtk_arrow_new().  The direction or
  44  * style of an arrow can be changed after creation by using gtk_arrow_set().
  45  */
  46
  47 #include "config.h"
  48 #include <math.h>
  49 #include "gtkarrow.h"
  50 #include "gtksizerequest.h"
  51 #include "gtktypebuiltins.h"
  52 #include "gtkprivate.h"
  53 #include "gtkintl.h"
  54
  55 #define MIN_ARROW_SIZE  15
  56
  57 struct _GtkArrowPrivate
  58 {
  59   gint16 arrow_type;
  60   gint16 shadow_type;
  61 };
  62
  63 enum {
  64   PROP_0,
  65   PROP_ARROW_TYPE,
  66   PROP_SHADOW_TYPE
  67 };
  68
  69
  70 static void     gtk_arrow_set_property (GObject        *object,
  71                                         guint           prop_id,
  72                                         const GValue   *value,
  73                                         GParamSpec     *pspec);
  74 static void     gtk_arrow_get_property (GObject        *object,
  75                                         guint           prop_id,
  76                                         GValue         *value,
  77                                         GParamSpec     *pspec);
  78 static gboolean gtk_arrow_draw         (GtkWidget      *widget,
  79                                         cairo_t        *cr);
  80
  81 static void     gtk_arrow_get_preferred_width         (GtkWidget           *widget,
  82                                                        gint                *minimum_size,
  83                                                        gint                *natural_size);
  84 static void     gtk_arrow_get_preferred_height        (GtkWidget           *widget,
  85                                                        gint                *minimum_size,
  86                                                        gint                *natural_size);
  87
  88 G_DEFINE_TYPE (GtkArrow, gtk_arrow, GTK_TYPE_MISC)
  89
  90
  91 static void
  92 gtk_arrow_class_init (GtkArrowClass *class)
  93 {
  94   GObjectClass *gobject_class;
  95   GtkWidgetClass *widget_class;
  96
  97   gobject_class = (GObjectClass*) class;
  98   widget_class = (GtkWidgetClass*) class;
  99
 100   gobject_class->set_property = gtk_arrow_set_property;
 101   gobject_class->get_property = gtk_arrow_get_property;
 102
 103   widget_class->draw = gtk_arrow_draw;
 104   widget_class->get_preferred_width  = gtk_arrow_get_preferred_width;
 105   widget_class->get_preferred_height = gtk_arrow_get_preferred_height;
 106
 107   g_object_class_install_property (gobject_class,
 108                                    PROP_ARROW_TYPE,
 109                                    g_param_spec_enum ("arrow-type",
 110                                                       P_("Arrow direction"),
 111                                                       P_("The direction the arrow should point"),
 112                                                       GTK_TYPE_ARROW_TYPE,
 113                                                       GTK_ARROW_RIGHT,
 114                                                       GTK_PARAM_READWRITE));
 115
 116   g_object_class_install_property (gobject_class,
 117                                    PROP_SHADOW_TYPE,
 118                                    g_param_spec_enum ("shadow-type",
 119                                                       P_("Arrow shadow"),
 120                                                       P_("Appearance of the shadow surrounding the arrow"),
 121                                                       GTK_TYPE_SHADOW_TYPE,
 122                                                       GTK_SHADOW_OUT,
 123                                                       GTK_PARAM_READWRITE));
 124
 125   gtk_widget_class_install_style_property (widget_class,
 126                                            g_param_spec_float ("arrow-scaling",
 127                                                                P_("Arrow Scaling"),
 128                                                                P_("Amount of space used up by arrow"),
 129                                                                0.0, 1.0, 0.7,
 130                                                                GTK_PARAM_READABLE));
 131
 132   g_type_class_add_private (class, sizeof (GtkArrowPrivate));
 133 }
 134
 135 static void
 136 gtk_arrow_set_property (GObject         *object,
 137                         guint            prop_id,
 138                         const GValue    *value,
 139                         GParamSpec      *pspec)
 140 {
 141   GtkArrow *arrow = GTK_ARROW (object);
 142   GtkArrowPrivate *priv = arrow->priv;
 143
 144   switch (prop_id)
 145     {
 146     case PROP_ARROW_TYPE:
 147       gtk_arrow_set (arrow,
 148                      g_value_get_enum (value),
 149                      priv->shadow_type);
 150       break;
 151     case PROP_SHADOW_TYPE:
 152       gtk_arrow_set (arrow,
 153                      priv->arrow_type,
 154                      g_value_get_enum (value));
 155       break;
 156     default:
 157       G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, pspec);
 158       break;
 159     }
 160 }
 161
 162 static void
 163 gtk_arrow_get_property (GObject         *object,
 164                         guint            prop_id,
 165                         GValue          *value,
 166                         GParamSpec      *pspec)
 167 {
 168   GtkArrow *arrow = GTK_ARROW (object);
 169   GtkArrowPrivate *priv = arrow->priv;
 170
 171   switch (prop_id)
 172     {
 173     case PROP_ARROW_TYPE:
 174       g_value_set_enum (value, priv->arrow_type);
 175       break;
 176     case PROP_SHADOW_TYPE:
 177       g_value_set_enum (value, priv->shadow_type);
 178       break;
 179     default:
 180       G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, pspec);
 181       break;
 182     }
 183 }
 184
 185 static void
 186 gtk_arrow_init (GtkArrow *arrow)
 187 {
 188   GtkArrowPrivate *priv;
 189
 190   arrow->priv = G_TYPE_INSTANCE_GET_PRIVATE (arrow,
 191                                              GTK_TYPE_ARROW,
 192                                              GtkArrowPrivate);
 193   priv = arrow->priv;
 194
 195   gtk_widget_set_has_window (GTK_WIDGET (arrow), FALSE);
 196
 197   priv->arrow_type = GTK_ARROW_RIGHT;
 198   priv->shadow_type = GTK_SHADOW_OUT;
 199 }
 200
 201 static void
 202 gtk_arrow_get_preferred_width (GtkWidget *widget,
 203                                gint      *minimum_size,
 204                                gint      *natural_size)
 205 {
 206   gint xpad;
 207
 208   gtk_misc_get_padding (GTK_MISC (widget), &xpad, NULL);
 209
 210   if (minimum_size)
 211     *minimum_size = MIN_ARROW_SIZE + xpad * 2;
 212
 213   if (natural_size)
 214     *natural_size = MIN_ARROW_SIZE + xpad * 2;
 215 }
 216
 217 static void
 218 gtk_arrow_get_preferred_height (GtkWidget *widget,
 219                                 gint      *minimum_size,
 220                                 gint      *natural_size)
 221 {
 222   gint ypad;
 223
 224   gtk_misc_get_padding (GTK_MISC (widget), NULL, &ypad);
 225
 226   if (minimum_size)
 227     *minimum_size = MIN_ARROW_SIZE + ypad * 2;
 228
 229   if (natural_size)
 230     *natural_size = MIN_ARROW_SIZE + ypad * 2;
 231 }
 232
 233
 234 /**
 235  * gtk_arrow_new:
 236  * @arrow_type: a valid #GtkArrowType.
 237  * @shadow_type: a valid #GtkShadowType.
 238  *
 239  * Creates a new #GtkArrow widget.
 240  *
 241  * Returns: the new #GtkArrow widget.
 242  */
 243 GtkWidget*
 244 gtk_arrow_new (GtkArrowType  arrow_type,
 245                GtkShadowType shadow_type)
 246 {
 247   GtkArrowPrivate *priv;
 248   GtkArrow *arrow;
 249
 250   arrow = g_object_new (GTK_TYPE_ARROW, NULL);
 251
 252   priv = arrow->priv;
 253
 254   priv->arrow_type = arrow_type;
 255   priv->shadow_type = shadow_type;
 256
 257   return GTK_WIDGET (arrow);
 258 }
 259
 260 /**
 261  * gtk_arrow_set:
 262  * @arrow: a widget of type #GtkArrow.
 263  * @arrow_type: a valid #GtkArrowType.
 264  * @shadow_type: a valid #GtkShadowType.
 265  *
 266  * Sets the direction and style of the #GtkArrow, @arrow.
 267  */
 268 void
 269 gtk_arrow_set (GtkArrow      *arrow,
 270                GtkArrowType   arrow_type,
 271                GtkShadowType  shadow_type)
 272 {
 273   GtkArrowPrivate *priv;
 274   GtkWidget *widget;
 275
 276   g_return_if_fail (GTK_IS_ARROW (arrow));
 277
 278   priv = arrow->priv;
 279
 280   if (priv->arrow_type != arrow_type
 281       || priv->shadow_type != shadow_type)
 282     {
 283       g_object_freeze_notify (G_OBJECT (arrow));
 284
 285       if ((GtkArrowType) priv->arrow_type != arrow_type)
 286         {
 287           priv->arrow_type = arrow_type;
 288           g_object_notify (G_OBJECT (arrow), "arrow-type");
 289         }
 290
 291       if (priv->shadow_type != shadow_type)
 292         {
 293           priv->shadow_type = shadow_type;
 294           g_object_notify (G_OBJECT (arrow), "shadow-type");
 295         }
 296
 297       g_object_thaw_notify (G_OBJECT (arrow));
 298
 299       widget = GTK_WIDGET (arrow);
 300       if (gtk_widget_is_drawable (widget))
 301         gtk_widget_queue_draw (widget);
 302     }
 303 }
 304
 305
 306 static gboolean
 307 gtk_arrow_draw (GtkWidget *widget,
 308                 cairo_t   *cr)
 309 {
 310   GtkArrow *arrow = GTK_ARROW (widget);
 311   GtkArrowPrivate *priv = arrow->priv;
 312   GtkMisc *misc = GTK_MISC (widget);
 313   GtkStyleContext *context;
 314   GtkStateFlags state;
 315   gdouble x, y;
 316   gint width, height;
 317   gint extent;
 318   gint xpad, ypad;
 319   gfloat xalign, yalign;
 320   GtkArrowType effective_arrow_type;
 321   gfloat arrow_scaling;
 322   gdouble angle;
 323
 324   if (priv->arrow_type == GTK_ARROW_NONE)
 325     return FALSE;
 326
 327   context = gtk_widget_get_style_context (widget);
 328   gtk_widget_style_get (widget, "arrow-scaling", &arrow_scaling, NULL);
 329
 330   gtk_misc_get_padding (misc, &xpad, &ypad);
 331   gtk_misc_get_alignment (misc, &xalign, &yalign);
 332
 333   width = gtk_widget_get_allocated_width (widget);
 334   height = gtk_widget_get_allocated_height (widget);
 335
 336   extent = MIN (width - 2 * xpad, height - 2 * ypad) * arrow_scaling;
 337   effective_arrow_type = priv->arrow_type;
 338
 339   if (gtk_widget_get_direction (widget) != GTK_TEXT_DIR_LTR)
 340     {
 341       xalign = 1.0 - xalign;
 342       if (priv->arrow_type == GTK_ARROW_LEFT)
 343         effective_arrow_type = GTK_ARROW_RIGHT;
 344       else if (priv->arrow_type == GTK_ARROW_RIGHT)
 345         effective_arrow_type = GTK_ARROW_LEFT;
 346     }
 347
 348   x = xpad + ((width  - extent) * xalign);
 349   y = ypad + ((height - extent) * yalign);
 350
 351   switch (effective_arrow_type)
 352     {
 353     case GTK_ARROW_UP:
 354       angle = 0;
 355       break;
 356     case GTK_ARROW_RIGHT:
 357       angle = G_PI / 2;
 358       break;
 359     case GTK_ARROW_DOWN:
 360       angle = G_PI;
 361       break;
 362     case GTK_ARROW_LEFT:
 363     default:
 364       angle = (3 * G_PI) / 2;
 365       break;
 366     }
 367
 368   gtk_style_context_save (context);
 369
 370   state = gtk_widget_get_state_flags (widget);
 371   gtk_style_context_set_state (context, state);
 372   gtk_render_arrow (context, cr, angle, x, y, extent);
 373
 374   gtk_style_context_restore (context);
 375
 376   return FALSE;
 377 }