src/geanywraplabel.c

   1 /*
   2  *      geanywraplabel.c - this file is part of Geany, a fast and lightweight IDE
   3  *
   4  *      Copyright 2009-2011 Enrico Tröger <enrico(dot)troeger(at)uvena(dot)de>
   5  *      Copyright 2009-2011 Nick Treleaven <nick(dot)treleaven(at)btinternet(dot)com>
   6  *
   7  *      This program is free software; you can redistribute it and/or modify
   8  *      it under the terms of the GNU General Public License as published by
   9  *      the Free Software Foundation; either version 2 of the License, or
  10  *      (at your option) any later version.
  11  *
  12  *      This program is distributed in the hope that it will be useful,
  13  *      but WITHOUT ANY WARRANTY; without even the implied warranty of
  14  *      MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  15  *      GNU General Public License for more details.
  16  *
  17  *      You should have received a copy of the GNU General Public License
  18  *      along with this program; if not, write to the Free Software
  19  *      Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
  20  */
  21
  22 /*
  23  * A GtkLabel subclass that can wrap to any width, unlike GtkLabel which has a fixed wrap point.
  24  * (inspired by libview's WrapLabel, http://view.sourceforge.net)
  25  */
  26
  27
  28 #include "geany.h"
  29 #include "utils.h"
  30 #include "geanywraplabel.h"
  31
  32
  33
  34 struct _GeanyWrapLabelClass
  35 {
  36         GtkLabelClass parent_class;
  37 };
  38
  39 typedef struct
  40 {
  41         gint wrap_width;
  42         gint wrap_height;
  43 } GeanyWrapLabelPrivate;
  44
  45 struct _GeanyWrapLabel
  46 {
  47         GtkLabel parent;
  48         GeanyWrapLabelPrivate *priv;
  49 };
  50
  51
  52 static void geany_wrap_label_size_request       (GtkWidget *widget, GtkRequisition *req);
  53 static void geany_wrap_label_size_allocate      (GtkWidget *widget, GtkAllocation *alloc);
  54 static gboolean geany_wrap_label_expose         (GtkWidget *widget, GdkEventExpose *event);
  55 static void geany_wrap_label_set_wrap_width     (GtkWidget *widget, gint width);
  56 static void geany_wrap_label_label_notify       (GObject *object, GParamSpec *pspec, gpointer data);
  57
  58 G_DEFINE_TYPE(GeanyWrapLabel, geany_wrap_label, GTK_TYPE_LABEL)
  59
  60
  61 static void geany_wrap_label_class_init(GeanyWrapLabelClass *klass)
  62 {
  63         GtkWidgetClass *widget_class = GTK_WIDGET_CLASS(klass);
  64
  65         widget_class->size_request = geany_wrap_label_size_request;
  66         widget_class->size_allocate = geany_wrap_label_size_allocate;
  67         widget_class->expose_event = geany_wrap_label_expose;
  68
  69         g_type_class_add_private(klass, sizeof (GeanyWrapLabelPrivate));
  70 }
  71
  72
  73 static void geany_wrap_label_init(GeanyWrapLabel *self)
  74 {
  75         self->priv = G_TYPE_INSTANCE_GET_PRIVATE(self,
  76                 GEANY_WRAP_LABEL_TYPE, GeanyWrapLabelPrivate);
  77
  78         self->priv->wrap_width = 0;
  79         self->priv->wrap_height = 0;
  80
  81         g_signal_connect(self, "notify::label", G_CALLBACK(geany_wrap_label_label_notify), NULL);
  82         gtk_misc_set_alignment(GTK_MISC(self), 0.0, 0.0);
  83 }
  84
  85
  86 /* Sets the point at which the text should wrap. */
  87 static void geany_wrap_label_set_wrap_width(GtkWidget *widget, gint width)
  88 {
  89         GeanyWrapLabel *self = GEANY_WRAP_LABEL(widget);
  90         PangoLayout *layout;
  91
  92         if (width <= 0)
  93                 return;
  94
  95         layout = gtk_label_get_layout(GTK_LABEL(widget));
  96
  97         /*
  98         * We may need to reset the wrap width, so do this regardless of whether
  99         * or not we've changed the width.
 100         */
 101         pango_layout_set_width(layout, width * PANGO_SCALE);
 102         pango_layout_set_wrap(layout, PANGO_WRAP_WORD_CHAR);
 103         pango_layout_get_pixel_size(layout, NULL, &self->priv->wrap_height);
 104
 105         if (self->priv->wrap_width != width)
 106         {
 107                 self->priv->wrap_width = width;
 108                 gtk_widget_queue_resize(widget);
 109         }
 110 }
 111
 112
 113 /* updates the wrap width when the label text changes */
 114 static void geany_wrap_label_label_notify(GObject *object, GParamSpec *pspec, gpointer data)
 115 {
 116         GeanyWrapLabel *self = GEANY_WRAP_LABEL(object);
 117
 118         geany_wrap_label_set_wrap_width(GTK_WIDGET(object), self->priv->wrap_width);
 119 }
 120
 121
 122 /* makes sure the layout is setup for rendering and chains to parent renderer */
 123 static gboolean geany_wrap_label_expose(GtkWidget *widget, GdkEventExpose *event)
 124 {
 125         GeanyWrapLabel *self = GEANY_WRAP_LABEL(widget);
 126         PangoLayout *layout = gtk_label_get_layout(GTK_LABEL(widget));
 127
 128         pango_layout_set_width(layout, self->priv->wrap_width * PANGO_SCALE);
 129         pango_layout_set_wrap(layout, PANGO_WRAP_WORD_CHAR);
 130
 131         return (* GTK_WIDGET_CLASS(geany_wrap_label_parent_class)->expose_event)(widget, event);
 132 }
 133
 134
 135 /* Forces the height to be the size necessary for the Pango layout, while allowing the
 136  * width to be flexible. */
 137 static void geany_wrap_label_size_request(GtkWidget *widget, GtkRequisition *req)
 138 {
 139         req->width = 0;
 140         req->height = GEANY_WRAP_LABEL(widget)->priv->wrap_height;
 141 }
 142
 143
 144 /* Sets the wrap width to the width allocated to us. */
 145 static void geany_wrap_label_size_allocate(GtkWidget *widget, GtkAllocation *alloc)
 146 {
 147         (* GTK_WIDGET_CLASS(geany_wrap_label_parent_class)->size_allocate)(widget, alloc);
 148
 149         geany_wrap_label_set_wrap_width(widget, alloc->width);
 150 }
 151
 152
 153 GtkWidget *geany_wrap_label_new(const gchar *text)
 154 {
 155         return g_object_new(GEANY_WRAP_LABEL_TYPE, "label", text, NULL);
 156 }