gtk2/gtk/gtklabel.c

/* 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., 675 Mass Ave, Cambridge, MA 02139, USA.
 */
#include <string.h>
#include "gtklabel.h"


static void gtk_label_class_init   (GtkLabelClass  *klass);
static void gtk_label_init         (GtkLabel       *label);
static void gtk_label_destroy      (GtkObject      *object);
static void gtk_label_size_request (GtkWidget      *widget,
				    GtkRequisition *requisition);
static gint gtk_label_expose       (GtkWidget      *widget,
				    GdkEventExpose *event);


static GtkMiscClass *parent_class = NULL;


guint
gtk_label_get_type ()
{
  static guint label_type = 0;

  if (!label_type)
    {
      GtkTypeInfo label_info =
      {
	"GtkLabel",
	sizeof (GtkLabel),
	sizeof (GtkLabelClass),
	(GtkClassInitFunc) gtk_label_class_init,
	(GtkObjectInitFunc) gtk_label_init,
	(GtkArgFunc) NULL,
      };

      label_type = gtk_type_unique (gtk_misc_get_type (), &label_info);
    }

  return label_type;
}

void
gtk_label_class_init (GtkLabelClass *class)
{
  GtkObjectClass *object_class;
  GtkWidgetClass *widget_class;

  object_class = (GtkObjectClass*) class;
  widget_class = (GtkWidgetClass*) class;

  parent_class = gtk_type_class (gtk_misc_get_type ());

  object_class->destroy = gtk_label_destroy;

  widget_class->size_request = gtk_label_size_request;
  widget_class->expose_event = gtk_label_expose;
}

void
gtk_label_init (GtkLabel *label)
{
  GTK_WIDGET_SET_FLAGS (label, GTK_NO_WINDOW);

  label->label = NULL;
  label->row = NULL;
  label->jtype = GTK_JUSTIFY_CENTER;
}

GtkWidget*
gtk_label_new (const char *str)
{
  GtkLabel *label;

  g_return_val_if_fail (str != NULL, NULL);

  label = gtk_type_new (gtk_label_get_type ());

  gtk_label_set (label, str);

  return GTK_WIDGET (label);
}

void
gtk_label_set (GtkLabel *label,
	       const char *str)
{
  char* p;

  g_return_if_fail (label != NULL);
  g_return_if_fail (GTK_IS_LABEL (label));
  g_return_if_fail (str != NULL);

  if (label->label)
    g_free (label->label);
  label->label = g_strdup (str);

  if (label->row)
    g_slist_free (label->row);
  label->row = NULL;
  label->row = g_slist_append (label->row, label->label);
  p = label->label;
  while ((p = strchr(p, '\n')))
    label->row = g_slist_append (label->row, ++p);

  if (GTK_WIDGET_VISIBLE (label))
    {
      if (GTK_WIDGET_MAPPED (label))
	gdk_window_clear_area (GTK_WIDGET (label)->window,
			       GTK_WIDGET (label)->allocation.x,
			       GTK_WIDGET (label)->allocation.y,
			       GTK_WIDGET (label)->allocation.width,
			       GTK_WIDGET (label)->allocation.height);

      gtk_widget_queue_resize (GTK_WIDGET (label));
    }
}

void
gtk_label_set_justify (GtkLabel *label, GtkJustification jtype)
{
  g_return_if_fail (label != NULL);
  g_return_if_fail (GTK_IS_LABEL (label));

  if ((GtkJustification) label->jtype != jtype)
    {
      label->jtype = jtype;
      
      if (GTK_WIDGET_VISIBLE (label))
        {
          if (GTK_WIDGET_MAPPED (label))
            gdk_window_clear_area (GTK_WIDGET (label)->window,
                                   GTK_WIDGET (label)->allocation.x,
                                   GTK_WIDGET (label)->allocation.y,
                                   GTK_WIDGET (label)->allocation.width,
                                   GTK_WIDGET (label)->allocation.height);
          
          gtk_widget_queue_resize (GTK_WIDGET (label));
        }
    }
}

void
gtk_label_get (GtkLabel  *label,
	       char     **str)
{
  g_return_if_fail (label != NULL);
  g_return_if_fail (GTK_IS_LABEL (label));
  g_return_if_fail (str != NULL);

  *str = label->label;
}


static void
gtk_label_destroy (GtkObject *object)
{
  GtkLabel *label;

  g_return_if_fail (object != NULL);
  g_return_if_fail (GTK_IS_LABEL (object));

  label = GTK_LABEL (object);

  if (GTK_WIDGET (object)->parent &&
      GTK_WIDGET_MAPPED (object))
    gtk_widget_unmap (GTK_WIDGET (object));

  g_free (label->label);
  g_slist_free (label->row);

  if (GTK_OBJECT_CLASS (parent_class)->destroy)
    (* GTK_OBJECT_CLASS (parent_class)->destroy) (object);
}

static void
gtk_label_size_request (GtkWidget      *widget,
			GtkRequisition *requisition)
{
  GtkLabel *label;
  GSList *row;
  gint width;

  g_return_if_fail (widget != NULL);
  g_return_if_fail (GTK_IS_LABEL (widget));
  g_return_if_fail (requisition != NULL);

  label = GTK_LABEL (widget);

  row = label->row;
  width = 0;
  while (row)
    {
      if (row->next)
  	  width = MAX (width,
                       gdk_text_width (GTK_WIDGET (label)->style->font, row->data,
                                       (gchar*) row->next->data - (gchar*) row->data));
      else
        width = MAX (width, gdk_string_width (GTK_WIDGET (label)->style->font, row->data));
      row = row->next;
    }
  
  requisition->width = width + label->misc.xpad * 2;
  requisition->height = ((GTK_WIDGET (label)->style->font->ascent +
                          GTK_WIDGET (label)->style->font->descent + 2) *
                         g_slist_length(label->row) +
                         label->misc.ypad * 2);
}

static gint
gtk_label_expose (GtkWidget      *widget,
		  GdkEventExpose *event)
{
  GtkLabel *label;
  GtkMisc *misc;
  GSList *row;
  gint state;
  gint offset;
  gint len;
  gint maxl;
  gint x, y;

  g_return_val_if_fail (widget != NULL, FALSE);
  g_return_val_if_fail (GTK_IS_LABEL (widget), FALSE);
  g_return_val_if_fail (event != NULL, FALSE);

  if (GTK_WIDGET_VISIBLE (widget) && GTK_WIDGET_MAPPED (widget))
    {
      label = GTK_LABEL (widget);
      misc = GTK_MISC (widget);

      state = widget->state;
      if (!GTK_WIDGET_IS_SENSITIVE (widget))
	state = GTK_STATE_INSENSITIVE;

      /* We only draw the label if we have been allocated at least as
       *  much space as we requested. If we have less space than we
       *  need to draw the string then we _should_ have asked our
       *  parent container to resize and a new allocation _should_
       *  be forthcoming so there is no reason to redraw (incorrectly)
       *  here.
       */
      if ((widget->allocation.width >= widget->requisition.width) &&
	  (widget->allocation.height >= widget->requisition.height))
	{
	  maxl = widget->requisition.width - misc->xpad * 2;
	  x = widget->allocation.x + misc->xpad +
	       (widget->allocation.width - widget->requisition.width) * misc->xalign + 0.5;
	  y = (widget->allocation.y * (1.0 - misc->yalign) +
	       (widget->allocation.y + widget->allocation.height - (widget->requisition.height -
								    misc->ypad * 2)) *
	       misc->yalign + widget->style->font->ascent) + 1.5;
          
	  row = label->row;
	  while (row && row->next)
            {
              len = (gchar*) row->next->data - (gchar*) row->data;
              offset = 0;
              if (label->jtype == GTK_JUSTIFY_CENTER)
	    	offset = (maxl - gdk_text_width (widget->style->font, row->data, len)) / 2;
              else if (label->jtype == GTK_JUSTIFY_RIGHT)
	    	offset = (maxl - gdk_text_width (widget->style->font, row->data, len));
              if (state == GTK_STATE_INSENSITIVE)
                gdk_draw_text (widget->window, widget->style->font,
                               widget->style->white_gc,
                               offset + x + 1, y + 1, row->data, len);
              
              gdk_draw_text (widget->window, widget->style->font,
                             widget->style->fg_gc[state],
                             offset + x, y, row->data, len);
              row = row->next;
              y += widget->style->font->ascent + widget->style->font->descent + 2;
            }
          
	 /* COMMENT: we can avoid gdk_text_width() calls here storing in label->row
	    the widths of the rows calculated in gtk_label_set.
	    Once we have a wrapping interface we can support GTK_JUSTIFY_FILL.
	  */
	 offset = 0;
	 if (label->jtype == GTK_JUSTIFY_CENTER)
           offset = (maxl - gdk_string_width (widget->style->font, row->data)) / 2;
	 else if (label->jtype == GTK_JUSTIFY_RIGHT)
           offset = (maxl - gdk_string_width (widget->style->font, row->data));
	 if (state == GTK_STATE_INSENSITIVE)
	   gdk_draw_string (widget->window, widget->style->font,
                            widget->style->white_gc,
                            offset + x + 1, y + 1, row->data);
         
	 gdk_draw_string (widget->window, widget->style->font,
                          widget->style->fg_gc[state],
                          offset + x, y, row->data);

         /*
         gdk_draw_rectangle (widget->window,
                             widget->style->bg_gc[GTK_STATE_SELECTED], FALSE,
                             widget->allocation.x, widget->allocation.y,
                             widget->allocation.width - 1, widget->allocation.height - 1);
                             */
	}
      else
	{
	  /*
	  g_print ("gtk_label_expose: allocation too small: %d %d ( %d %d )\n",
		   widget->allocation.width, widget->allocation.height,
		   widget->requisition.width, widget->requisition.height);
		   */
	}
    }

  return TRUE;
}