gtklabel.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., 675 Mass Ave, Cambridge, MA 02139, 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 <math.h>
#include <string.h>
#include "gtklabel.h"
#include "gdk/gdkkeysyms.h"
#include "gdk/gdki18n.h"

enum {
  ARG_0,
  ARG_LABEL,
  ARG_PATTERN,
  ARG_JUSTIFY,
  ARG_WRAP
};

typedef struct _GtkLabelULine GtkLabelULine;
struct _GtkLabelWord
{
  GdkWChar *beginning;
  gint length;
  
  /* FIXME:
   * We need (space,width) only before we've set (x,y), so to save
   * memory, these pairs should really be wrapped in a union.
   * I haven't yet figured out how to do this without making the code
   * look ugly. 
   */
  gint space;
  gint width;
  gint x;
  gint y;
  GtkLabelWord *next;
  gint uline_y;
  GtkLabelULine *uline;
};

struct _GtkLabelULine
{
  gint x1;
  gint x2;
  gint y;
  GtkLabelULine *next;
};

static void gtk_label_class_init   (GtkLabelClass  *klass);
static void gtk_label_init	   (GtkLabel	   *label);
static void gtk_label_set_arg	   (GtkObject	   *object,
				    GtkArg	   *arg,
				    guint	    arg_id);
static void gtk_label_get_arg	   (GtkObject      *object,
				    GtkArg	   *arg,
				    guint	    arg_id);
static void gtk_label_finalize	   (GtkObject	   *object);
static void gtk_label_size_request (GtkWidget	   *widget,
				    GtkRequisition *requisition);
static void gtk_label_style_set    (GtkWidget      *widget,
				    GtkStyle       *previous_style);
static gint gtk_label_expose	   (GtkWidget	   *widget,
				    GdkEventExpose *event);

static GtkLabelWord*  gtk_label_word_alloc          (void);
static GtkLabelULine* gtk_label_uline_alloc         (void);
static void           gtk_label_free_words          (GtkLabel     *label);
static void           gtk_label_free_ulines         (GtkLabelWord *word);
static gint           gtk_label_split_text          (GtkLabel     *label);


static GtkMiscClass *parent_class = NULL;

static GMemChunk *word_chunk = NULL;
static GMemChunk *uline_chunk = NULL;

GtkType
gtk_label_get_type (void)
{
  static GtkType label_type = 0;
  
  if (!label_type)
    {
      static const GtkTypeInfo label_info =
      {
	"GtkLabel",
	sizeof (GtkLabel),
	sizeof (GtkLabelClass),
	(GtkClassInitFunc) gtk_label_class_init,
	(GtkObjectInitFunc) gtk_label_init,
        /* reserved_1 */ NULL,
	/* reserved_2 */ NULL,
	(GtkClassInitFunc) NULL,
      };
      
      label_type = gtk_type_unique (GTK_TYPE_MISC, &label_info);
      gtk_type_set_chunk_alloc (label_type, 32);
    }
  
  return label_type;
}

static 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_TYPE_MISC);
  
  gtk_object_add_arg_type ("GtkLabel::label", GTK_TYPE_STRING, GTK_ARG_READWRITE, ARG_LABEL);
  gtk_object_add_arg_type ("GtkLabel::pattern", GTK_TYPE_STRING, GTK_ARG_READWRITE, ARG_PATTERN);
  gtk_object_add_arg_type ("GtkLabel::justify", GTK_TYPE_JUSTIFICATION, GTK_ARG_READWRITE, ARG_JUSTIFY);
  gtk_object_add_arg_type ("GtkLabel::wrap", GTK_TYPE_BOOL, GTK_ARG_READWRITE, ARG_WRAP);
  
  object_class->set_arg = gtk_label_set_arg;
  object_class->get_arg = gtk_label_get_arg;
  object_class->finalize = gtk_label_finalize;
  
  widget_class->size_request = gtk_label_size_request;
  widget_class->style_set = gtk_label_style_set;
  widget_class->expose_event = gtk_label_expose;
}

static void
gtk_label_set_arg (GtkObject	  *object,
		   GtkArg	  *arg,
		   guint	   arg_id)
{
  GtkLabel *label;
  
  label = GTK_LABEL (object);
  
  switch (arg_id)
    {
    case ARG_LABEL:
      gtk_label_set_text (label, GTK_VALUE_STRING (*arg));
      break;
    case ARG_PATTERN:
      gtk_label_set_pattern (label, GTK_VALUE_STRING (*arg));
      break;
    case ARG_JUSTIFY:
      gtk_label_set_justify (label, GTK_VALUE_ENUM (*arg));
      break;
    case ARG_WRAP:
      gtk_label_set_line_wrap (label, GTK_VALUE_BOOL (*arg));
      break;	  
    default:
      break;
    }
}

static void
gtk_label_get_arg (GtkObject	  *object,
		   GtkArg	  *arg,
		   guint	   arg_id)
{
  GtkLabel *label;
  
  label = GTK_LABEL (object);
  
  switch (arg_id)
    {
    case ARG_LABEL:
      GTK_VALUE_STRING (*arg) = g_strdup (label->label);
      break;
    case ARG_PATTERN:
      GTK_VALUE_STRING (*arg) = g_strdup (label->pattern);
      break;
    case ARG_JUSTIFY:
      GTK_VALUE_ENUM (*arg) = label->jtype;
      break;
    case ARG_WRAP:
      GTK_VALUE_BOOL (*arg) = label->wrap;
      break;
    default:
      arg->type = GTK_TYPE_INVALID;
      break;
    }
}

static void
gtk_label_init (GtkLabel *label)
{
  GTK_WIDGET_SET_FLAGS (label, GTK_NO_WINDOW);
  
  label->label = NULL;
  label->label_wc = NULL;
  label->pattern = NULL;

  label->words = NULL;

  label->max_width = 0;
  label->jtype = GTK_JUSTIFY_CENTER;
  label->wrap = FALSE;
  
  gtk_label_set_text (label, "");
}

GtkWidget*
gtk_label_new (const gchar *str)
{
  GtkLabel *label;
  
  label = gtk_type_new (GTK_TYPE_LABEL);

  if (str && *str)
    gtk_label_set_text (label, str);
  
  return GTK_WIDGET (label);
}

static inline void
gtk_label_set_text_internal (GtkLabel *label,
			     gchar    *str,
			     GdkWChar *str_wc)
{
  gtk_label_free_words (label);
      
  g_free (label->label);
  g_free (label->label_wc);
  
  label->label = str;
  label->label_wc = str_wc;
  
  gtk_widget_queue_resize (GTK_WIDGET (label));
}

void
gtk_label_set_text (GtkLabel    *label,
		    const gchar *str)
{
  GdkWChar *str_wc;
  gint len;
  gint wc_len;
  
  g_return_if_fail (GTK_IS_LABEL (label));
  if (!str)
    str = "";

  if (!label->label || strcmp (label->label, str))
    {
      /* Convert text to wide characters */
      len = strlen (str);
      str_wc = g_new (GdkWChar, len + 1);
      wc_len = gdk_mbstowcs (str_wc, str, len + 1);
      if (wc_len >= 0)
	{
	  str_wc[wc_len] = '\0';
	  gtk_label_set_text_internal (label, g_strdup (str), str_wc);
	}
      else
	g_free (str_wc);
    }
}

void
gtk_label_set_pattern (GtkLabel	   *label,
		       const gchar *pattern)
{
  g_return_if_fail (GTK_IS_LABEL (label));
  
  gtk_label_free_words (label);
  
  g_free (label->pattern);
  label->pattern = g_strdup (pattern);

  gtk_widget_queue_resize (GTK_WIDGET (label));
}

void
gtk_label_set_justify (GtkLabel        *label,
		       GtkJustification jtype)
{
  g_return_if_fail (GTK_IS_LABEL (label));
  g_return_if_fail (jtype >= GTK_JUSTIFY_LEFT && jtype <= GTK_JUSTIFY_FILL);
  
  if ((GtkJustification) label->jtype != jtype)
    {
      gtk_label_free_words (label);
      
      label->jtype = jtype;

      gtk_widget_queue_resize (GTK_WIDGET (label));
    }
}

void
gtk_label_set_line_wrap (GtkLabel *label,
			 gboolean  wrap)
{
  g_return_if_fail (GTK_IS_LABEL (label));
  
  wrap = wrap != FALSE;
  
  if (label->wrap != wrap)
    {
      gtk_label_free_words (label);

      label->wrap = wrap;

      gtk_widget_queue_resize (GTK_WIDGET (label));
    }
}

void
gtk_label_get (GtkLabel *label,
	       gchar   **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_finalize (GtkObject *object)
{
  GtkLabel *label;
  
  g_return_if_fail (object != NULL);
  g_return_if_fail (GTK_IS_LABEL (object));
  
  label = GTK_LABEL (object);
  
  g_free (label->label);
  g_free (label->label_wc);
  g_free (label->pattern);

  gtk_label_free_words (label);

  GTK_OBJECT_CLASS (parent_class)->finalize (object);
}

static GtkLabelULine*
gtk_label_uline_alloc (void)
{
  GtkLabelULine *uline;
  
  if (!uline_chunk)
    uline_chunk = g_mem_chunk_create (GtkLabelWord, 32, G_ALLOC_AND_FREE);

  uline = g_chunk_new0 (GtkLabelULine, uline_chunk);
  
  uline->next = NULL;
  
  return uline;
}

static void
gtk_label_free_ulines (GtkLabelWord *word)
{
  while (word->uline)
    {
      GtkLabelULine *uline = word->uline;

      word->uline = uline->next;
      g_chunk_free (uline, uline_chunk);
    }
}

static GtkLabelWord*
gtk_label_word_alloc (void)
{
  GtkLabelWord * word;
  
  if (!word_chunk)
    word_chunk = g_mem_chunk_create (GtkLabelWord, 32, G_ALLOC_AND_FREE);
  
  word = g_chunk_new0 (GtkLabelWord, word_chunk);
  
  word->beginning = NULL;
  word->next = NULL;
  word->uline = NULL;

  return word;
}

static void
gtk_label_free_words (GtkLabel *label)
{
  while (label->words)
    {
      GtkLabelWord *word = label->words;

      label->words = word->next;

      gtk_label_free_ulines (word);

      g_chunk_free (word, word_chunk);
    }
}

static gint
gtk_label_split_text (GtkLabel *label)
{
  GtkLabelWord *word, **tailp;
  gint space_width, line_width, max_line_width;
  GdkWChar *str, *p;
  
  gtk_label_free_words (label);
  if (label->label == NULL)
    return 0;
  
  /* Split text at new-lines. */
  space_width = gdk_string_width (GTK_WIDGET (label)->style->font, " ");
  
  line_width = 0;
  max_line_width = 0;
  tailp = &label->words;
  str = label->label_wc;
  
  while (*str)
    {
      word = gtk_label_word_alloc ();
      
      if (str == label->label_wc || str[-1] == '\n')
	{
	  /* Paragraph break */
	  word->space = 0;
	  
	  max_line_width = MAX (line_width, max_line_width);
	  line_width = 0;
	}
      else if (str[0] == ' ')
	{
	  while (str[0] == ' ')
	    {
	      str++;
	      word->space += space_width;
	    }
	}
      else
	{
	  /* Regular inter-word space */
	  word->space = space_width;
	}
      
      word->beginning = str;
      
      word->length = 0;
      p = word->beginning;
      while (*p && *p != '\n')
	{
	  word->length++;
	  p++;
	}
      
      word->width = gdk_text_width_wc (GTK_WIDGET (label)->style->font, str, word->length);
      
      str += word->length;
      if (*str)
	str++;
      
      line_width += word->space + word->width;
      
      *tailp = word;
      tailp = &word->next;
    }
  
  /* Add an empty word to represent an empty line
   */
  if (str == label->label_wc || str[-1] == '\n')
    {
      word = gtk_label_word_alloc ();
      
      word->space = 0;
      word->beginning = str;
      word->length = 0;
      word->width = 0;
      
      *tailp = word;
      tailp = &word->next;
    }
  
  return MAX (line_width, max_line_width);
}

/* this needs to handle white space better. */
static gint
gtk_label_split_text_wrapped (GtkLabel *label)
{