gtkvscrollbar.c

gtk是linux一款强大的夸平台的图形化开发工具

/* GTK - The GIMP Toolkit
 * Copyright (C) 1995-1997 Peter Mattis, Spencer Kimball and Josh MacDonald
 *
 * This library is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Library General Public
 * License as published by the Free Software Foundation; either
 * version 2 of the License, or (at your option) any later version.
 *
 * This library is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 * Library General Public License for more details.
 *
 * You should have received a copy of the GNU Library General Public
 * License along with this library; if not, write to the
 * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
 * Boston, MA 02111-1307, USA.
 */

/*
 * Modified by the GTK+ Team and others 1997-1999.  See the AUTHORS
 * file for a list of people on the GTK+ Team.  See the ChangeLog
 * files for a list of changes.  These files are distributed with
 * GTK+ at ftp://ftp.gtk.org/pub/gtk/. 
 */

#include "gtkvscrollbar.h"
#include "gtksignal.h"
#include "gdk/gdkkeysyms.h"


#define EPSILON 0.01

#define RANGE_CLASS(w)  GTK_RANGE_CLASS (GTK_OBJECT (w)->klass)

enum {
  ARG_0,
  ARG_ADJUSTMENT
};

static void gtk_vscrollbar_class_init       (GtkVScrollbarClass *klass);
static void gtk_vscrollbar_init             (GtkVScrollbar      *vscrollbar);
static void gtk_vscrollbar_set_arg          (GtkObject          *object,
                                             GtkArg             *arg,
                                             guint               arg_id);
static void gtk_vscrollbar_get_arg          (GtkObject          *object,
                                             GtkArg             *arg,
                                             guint               arg_id);
static void gtk_vscrollbar_realize          (GtkWidget          *widget);
static void gtk_vscrollbar_size_allocate    (GtkWidget          *widget,
                                             GtkAllocation      *allocation);
static void gtk_vscrollbar_draw_step_forw   (GtkRange           *range);
static void gtk_vscrollbar_draw_step_back   (GtkRange           *range);
static void gtk_vscrollbar_slider_update    (GtkRange           *range);
static void gtk_vscrollbar_calc_slider_size (GtkVScrollbar      *vscrollbar);
static gint gtk_vscrollbar_trough_keys      (GtkRange *range,
                                             GdkEventKey *key,
                                             GtkScrollType *scroll,
                                             GtkTroughType *pos);


GtkType
gtk_vscrollbar_get_type (void)
{
  static GtkType vscrollbar_type = 0;
  
  if (!vscrollbar_type)
    {
      static const GtkTypeInfo vscrollbar_info =
      {
        "GtkVScrollbar",
        sizeof (GtkVScrollbar),
        sizeof (GtkVScrollbarClass),
        (GtkClassInitFunc) gtk_vscrollbar_class_init,
        (GtkObjectInitFunc) gtk_vscrollbar_init,
        /* reserved_1 */ NULL,
        /* reserved_2 */ NULL,
        (GtkClassInitFunc) NULL,
      };
      
      vscrollbar_type = gtk_type_unique (GTK_TYPE_SCROLLBAR, &vscrollbar_info);
    }
  
  return vscrollbar_type;
}

static void
gtk_vscrollbar_class_init (GtkVScrollbarClass *class)
{
  GtkObjectClass *object_class;
  GtkWidgetClass *widget_class;
  GtkRangeClass *range_class;
  
  object_class = (GtkObjectClass*) class;
  widget_class = (GtkWidgetClass*) class;
  range_class = (GtkRangeClass*) class;
  
  gtk_object_add_arg_type ("GtkVScrollbar::adjustment",
                           GTK_TYPE_ADJUSTMENT,
                           GTK_ARG_READWRITE | GTK_ARG_CONSTRUCT,
                           ARG_ADJUSTMENT);
  
  object_class->set_arg = gtk_vscrollbar_set_arg;
  object_class->get_arg = gtk_vscrollbar_get_arg;
  
  widget_class->realize = gtk_vscrollbar_realize;
  widget_class->size_allocate = gtk_vscrollbar_size_allocate;
  
  range_class->draw_step_forw = gtk_vscrollbar_draw_step_forw;
  range_class->draw_step_back = gtk_vscrollbar_draw_step_back;
  range_class->slider_update = gtk_vscrollbar_slider_update;
  range_class->trough_click = gtk_range_default_vtrough_click;
  range_class->trough_keys = gtk_vscrollbar_trough_keys;
  range_class->motion = gtk_range_default_vmotion;
}

static void
gtk_vscrollbar_set_arg (GtkObject          *object,
                        GtkArg             *arg,
                        guint               arg_id)
{
  GtkVScrollbar *vscrollbar;
  
  vscrollbar = GTK_VSCROLLBAR (object);
  
  switch (arg_id)
    {
    case ARG_ADJUSTMENT:
      gtk_range_set_adjustment (GTK_RANGE (vscrollbar), GTK_VALUE_POINTER (*arg));
      break;
    default:
      break;
    }
}

static void
gtk_vscrollbar_get_arg (GtkObject          *object,
                        GtkArg             *arg,
                        guint               arg_id)
{
  GtkVScrollbar *vscrollbar;
  
  vscrollbar = GTK_VSCROLLBAR (object);
  
  switch (arg_id)
    {
    case ARG_ADJUSTMENT:
      GTK_VALUE_POINTER (*arg) = GTK_RANGE (vscrollbar);
      break;
    default:
      arg->type = GTK_TYPE_INVALID;
      break;
    }
}

static void
gtk_vscrollbar_init (GtkVScrollbar *vscrollbar)
{
  GtkWidget *widget;
  GtkRequisition *requisition;
  
  widget = GTK_WIDGET (vscrollbar);
  requisition = &widget->requisition;
  
  requisition->width = (RANGE_CLASS (widget)->slider_width +
                        widget->style->klass->xthickness * 2);
  requisition->height = (RANGE_CLASS (widget)->min_slider_size +
                         RANGE_CLASS (widget)->stepper_size +
                         RANGE_CLASS (widget)->stepper_slider_spacing +
                         widget->style->klass->ythickness) * 2;
}

GtkWidget*
gtk_vscrollbar_new (GtkAdjustment *adjustment)
{
  GtkWidget *vscrollbar;
  
  vscrollbar = gtk_widget_new (GTK_TYPE_VSCROLLBAR,
			       "adjustment", adjustment,
			       NULL);
  
  return vscrollbar;
}


static void
gtk_vscrollbar_realize (GtkWidget *widget)
{
  GtkRange *range;
  GdkWindowAttr attributes;
  gint attributes_mask;
  
  g_return_if_fail (widget != NULL);
  g_return_if_fail (GTK_IS_VSCROLLBAR (widget));
  
  GTK_WIDGET_SET_FLAGS (widget, GTK_REALIZED);
  range = GTK_RANGE (widget);
  
  attributes.x = widget->allocation.x + (widget->allocation.width - widget->requisition.width) / 2;
  attributes.y = widget->allocation.y;
  attributes.width = widget->requisition.width;
  attributes.height = widget->allocation.height;
  attributes.wclass = GDK_INPUT_OUTPUT;
  attributes.window_type = GDK_WINDOW_CHILD;
  attributes.visual = gtk_widget_get_visual (widget);
  attributes.colormap = gtk_widget_get_colormap (widget);
  attributes.event_mask = gtk_widget_get_events (widget);
  attributes.event_mask |= (GDK_EXPOSURE_MASK |
                            GDK_BUTTON_PRESS_MASK |
                            GDK_BUTTON_RELEASE_MASK |
                            GDK_ENTER_NOTIFY_MASK |
                            GDK_LEAVE_NOTIFY_MASK);
  
  attributes_mask = GDK_WA_X | GDK_WA_Y | GDK_WA_VISUAL | GDK_WA_COLORMAP;
  widget->window = gdk_window_new (gtk_widget_get_parent_window (widget), &attributes, attributes_mask);
  
  range->trough = widget->window;
  gdk_window_ref (range->trough);
  
  attributes.x = widget->style->klass->xthickness;
  attributes.y = widget->style->klass->ythickness;
  attributes.width = RANGE_CLASS (widget)->stepper_size;
  attributes.height = RANGE_CLASS (widget)->stepper_size;
  
  range->step_back = gdk_window_new (range->trough, &attributes, attributes_mask);
  
  attributes.y = (widget->allocation.height -
                  widget->style->klass->ythickness -
                  RANGE_CLASS (widget)->stepper_size);
  
  range->step_forw = gdk_window_new (range->trough, &attributes, attributes_mask);