src/geanywraplabel.c

   1 /*
   2  *      geanywraplabel.c - this file is part of Geany, a fast and lightweight IDE
   3  *
   4  *      Copyright 2009 The Geany contributors
   5  *
   6  *      This program is free software; you can redistribute it and/or modify
   7  *      it under the terms of the GNU General Public License as published by
   8  *      the Free Software Foundation; either version 2 of the License, or
   9  *      (at your option) any later version.
  10  *
  11  *      This program is distributed in the hope that it will be useful,
  12  *      but WITHOUT ANY WARRANTY; without even the implied warranty of
  13  *      MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  14  *      GNU General Public License for more details.
  15  *
  16  *      You should have received a copy of the GNU General Public License along
  17  *      with this program; if not, write to the Free Software Foundation, Inc.,
  18  *      51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
  19  */
  20
  21 /*
  22  * A GtkLabel subclass that can wrap to any width, unlike GtkLabel which has a fixed wrap point.
  23  * (inspired by libview's WrapLabel, http://view.sourceforge.net)
  24  */
  25
  26 #ifdef HAVE_CONFIG_H
  27 # include "config.h"
  28 #endif
  29
  30 #include "geanywraplabel.h"
  31
  32
  33 struct _GeanyWrapLabelClass
  34 {
  35         GtkLabelClass parent_class;
  36 };
  37
  38 typedef struct
  39 {
  40         gint wrap_width;
  41         gint wrap_height;
  42 } GeanyWrapLabelPrivate;
  43
  44 struct _GeanyWrapLabel
  45 {
  46         GtkLabel parent;
  47         GeanyWrapLabelPrivate *priv;
  48 };
  49
  50
  51 static gboolean geany_wrap_label_draw(GtkWidget *widget, cairo_t *cr);
  52 static void geany_wrap_label_get_preferred_width (GtkWidget *widget,
  53                 gint *minimal_width, gint *natural_width);
  54 static void geany_wrap_label_get_preferred_height (GtkWidget *widget,
  55                 gint *minimal_height, gint *natural_height);
  56 static void geany_wrap_label_get_preferred_width_for_height (GtkWidget *widget,
  57                 gint height, gint *minimal_width, gint *natural_width);
  58 static void geany_wrap_label_get_preferred_height_for_width (GtkWidget *widget,
  59                 gint width, gint *minimal_height, gint *natural_height);
  60 static GtkSizeRequestMode geany_wrap_label_get_request_mode(GtkWidget *widget);
  61 static void geany_wrap_label_size_allocate      (GtkWidget *widget, GtkAllocation *alloc);
  62 static void geany_wrap_label_set_wrap_width     (GtkWidget *widget, gint width);
  63 static void geany_wrap_label_label_notify       (GObject *object, GParamSpec *pspec, gpointer data);
  64
  65 G_DEFINE_TYPE(GeanyWrapLabel, geany_wrap_label, GTK_TYPE_LABEL)
  66
  67
  68 static void geany_wrap_label_class_init(GeanyWrapLabelClass *klass)
  69 {
  70         GtkWidgetClass *widget_class = GTK_WIDGET_CLASS(klass);
  71
  72         widget_class->size_allocate = geany_wrap_label_size_allocate;
  73         widget_class->draw = geany_wrap_label_draw;
  74         widget_class->get_preferred_width = geany_wrap_label_get_preferred_width;
  75         widget_class->get_preferred_width_for_height = geany_wrap_label_get_preferred_width_for_height;
  76         widget_class->get_preferred_height = geany_wrap_label_get_preferred_height;
  77         widget_class->get_preferred_height_for_width = geany_wrap_label_get_preferred_height_for_width;
  78         widget_class->get_request_mode = geany_wrap_label_get_request_mode;
  79
  80         g_type_class_add_private(klass, sizeof (GeanyWrapLabelPrivate));
  81 }
  82
  83
  84 static void geany_wrap_label_init(GeanyWrapLabel *self)
  85 {
  86         self->priv = G_TYPE_INSTANCE_GET_PRIVATE(self,
  87                 GEANY_WRAP_LABEL_TYPE, GeanyWrapLabelPrivate);
  88
  89         self->priv->wrap_width = 0;
  90         self->priv->wrap_height = 0;
  91
  92         g_signal_connect(self, "notify::label", G_CALLBACK(geany_wrap_label_label_notify), NULL);
  93         gtk_misc_set_alignment(GTK_MISC(self), 0.0, 0.0);
  94 }
  95
  96
  97 /* Sets the point at which the text should wrap. */
  98 static void geany_wrap_label_set_wrap_width(GtkWidget *widget, gint width)
  99 {
 100         GeanyWrapLabel *self = GEANY_WRAP_LABEL(widget);
 101         PangoLayout *layout;
 102
 103         if (width <= 0)
 104                 return;
 105
 106         layout = gtk_label_get_layout(GTK_LABEL(widget));
 107
 108         /*
 109         * We may need to reset the wrap width, so do this regardless of whether
 110         * or not we've changed the width.
 111         */
 112         pango_layout_set_width(layout, width * PANGO_SCALE);
 113         pango_layout_set_wrap(layout, PANGO_WRAP_WORD_CHAR);
 114         pango_layout_get_pixel_size(layout, NULL, &self->priv->wrap_height);
 115
 116         if (self->priv->wrap_width != width)
 117         {
 118                 self->priv->wrap_width = width;
 119                 gtk_widget_queue_resize(widget);
 120         }
 121 }
 122
 123
 124 /* updates the wrap width when the label text changes */
 125 static void geany_wrap_label_label_notify(GObject *object, GParamSpec *pspec, gpointer data)
 126 {
 127         GeanyWrapLabel *self = GEANY_WRAP_LABEL(object);
 128
 129         geany_wrap_label_set_wrap_width(GTK_WIDGET(object), self->priv->wrap_width);
 130 }
 131
 132
 133 /* makes sure the layout is setup for rendering and chains to parent renderer */
 134 static gboolean geany_wrap_label_draw(GtkWidget *widget, cairo_t *cr)
 135 {
 136         GeanyWrapLabel *self = GEANY_WRAP_LABEL(widget);
 137         PangoLayout *layout = gtk_label_get_layout(GTK_LABEL(widget));
 138
 139         pango_layout_set_width(layout, self->priv->wrap_width * PANGO_SCALE);
 140         pango_layout_set_wrap(layout, PANGO_WRAP_WORD_CHAR);
 141
 142         return (* GTK_WIDGET_CLASS(geany_wrap_label_parent_class)->draw)(widget, cr);
 143 }
 144
 145
 146 static void geany_wrap_label_get_preferred_width (GtkWidget *widget,
 147                 gint *minimal_width, gint *natural_width)
 148 {
 149         *minimal_width = *natural_width = 0;
 150 }
 151
 152
 153 static void geany_wrap_label_get_preferred_width_for_height (GtkWidget *widget,
 154                 gint height, gint *minimal_width, gint *natural_width)
 155 {
 156         PangoLayout *layout = gtk_label_get_layout(GTK_LABEL(widget));;
 157
 158         pango_layout_set_height(layout, height * PANGO_SCALE);
 159         pango_layout_set_wrap(layout, PANGO_WRAP_WORD_CHAR);
 160         pango_layout_get_pixel_size(layout, natural_width, NULL);
 161
 162         *minimal_width = 0;
 163 }
 164
 165
 166 static void geany_wrap_label_get_preferred_height (GtkWidget *widget,
 167                 gint *minimal_height, gint *natural_height)
 168 {
 169         *minimal_height = *natural_height = GEANY_WRAP_LABEL(widget)->priv->wrap_height;
 170 }
 171
 172
 173 static void geany_wrap_label_get_preferred_height_for_width (GtkWidget *widget,
 174                 gint width, gint *minimal_height, gint *natural_height)
 175 {
 176         PangoLayout *layout = gtk_label_get_layout(GTK_LABEL(widget));
 177
 178         pango_layout_set_width(layout, width * PANGO_SCALE);
 179         pango_layout_set_wrap(layout, PANGO_WRAP_WORD_CHAR);
 180         pango_layout_get_pixel_size(layout, NULL, natural_height);
 181
 182         *minimal_height = *natural_height;
 183 }
 184
 185
 186 static GtkSizeRequestMode geany_wrap_label_get_request_mode(GtkWidget *widget)
 187 {
 188         return GTK_SIZE_REQUEST_WIDTH_FOR_HEIGHT;
 189 }
 190
 191
 192 /* Sets the wrap width to the width allocated to us. */
 193 static void geany_wrap_label_size_allocate(GtkWidget *widget, GtkAllocation *alloc)
 194 {
 195         GtkWidget *parent;
 196
 197         (* GTK_WIDGET_CLASS(geany_wrap_label_parent_class)->size_allocate)(widget, alloc);
 198
 199         geany_wrap_label_set_wrap_width(widget, alloc->width);
 200
 201         /* ask the parent to recompute our size, because it seems GTK size
 202          * caching is too aggressive */
 203         parent = gtk_widget_get_parent(widget);
 204         if (GTK_IS_CONTAINER(parent))
 205                 gtk_container_check_resize(GTK_CONTAINER(parent));
 206 }
 207
 208
 209 GtkWidget *geany_wrap_label_new(const gchar *text)
 210 {
 211         return g_object_new(GEANY_WRAP_LABEL_TYPE, "label", text, NULL);
 212 }