src/geanywraplabel.c

   1 /*
   2  *      geanywraplabel.c - this file is part of Geany, a fast and lightweight IDE
   3  *
   4  *      Copyright 2009-2012 Enrico Tröger <enrico(dot)troeger(at)uvena(dot)de>
   5  *      Copyright 2009-2012 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 along
  18  *      with this program; if not, write to the Free Software Foundation, Inc.,
  19  *      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 #ifdef HAVE_CONFIG_H
  28 # include "config.h"
  29 #endif
  30
  31 #include "geanywraplabel.h"
  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 #if GTK_CHECK_VERSION(3, 0, 0)
  53 static gboolean geany_wrap_label_draw(GtkWidget *widget, cairo_t *cr);
  54 static void geany_wrap_label_get_preferred_width (GtkWidget *widget,
  55                 gint *minimal_width, gint *natural_width);
  56 static void geany_wrap_label_get_preferred_height (GtkWidget *widget,
  57                 gint *minimal_height, gint *natural_height);
  58 static void geany_wrap_label_get_preferred_width_for_height (GtkWidget *widget,
  59                 gint height, gint *minimal_width, gint *natural_width);
  60 static void geany_wrap_label_get_preferred_height_for_width (GtkWidget *widget,
  61                 gint width, gint *minimal_height, gint *natural_height);
  62 static GtkSizeRequestMode geany_wrap_label_get_request_mode(GtkWidget *widget);
  63 #else
  64 static gboolean geany_wrap_label_expose         (GtkWidget *widget, GdkEventExpose *event);
  65 static void geany_wrap_label_size_request       (GtkWidget *widget, GtkRequisition *req);
  66 #endif
  67 static void geany_wrap_label_size_allocate      (GtkWidget *widget, GtkAllocation *alloc);
  68 static void geany_wrap_label_set_wrap_width     (GtkWidget *widget, gint width);
  69 static void geany_wrap_label_label_notify       (GObject *object, GParamSpec *pspec, gpointer data);
  70
  71 G_DEFINE_TYPE(GeanyWrapLabel, geany_wrap_label, GTK_TYPE_LABEL)
  72
  73
  74 static void geany_wrap_label_class_init(GeanyWrapLabelClass *klass)
  75 {
  76         GtkWidgetClass *widget_class = GTK_WIDGET_CLASS(klass);
  77
  78         widget_class->size_allocate = geany_wrap_label_size_allocate;
  79 #if GTK_CHECK_VERSION(3, 0, 0)
  80         widget_class->draw = geany_wrap_label_draw;
  81         widget_class->get_preferred_width = geany_wrap_label_get_preferred_width;
  82         widget_class->get_preferred_width_for_height = geany_wrap_label_get_preferred_width_for_height;
  83         widget_class->get_preferred_height = geany_wrap_label_get_preferred_height;
  84         widget_class->get_preferred_height_for_width = geany_wrap_label_get_preferred_height_for_width;
  85         widget_class->get_request_mode = geany_wrap_label_get_request_mode;
  86 #else
  87         widget_class->size_request = geany_wrap_label_size_request;
  88         widget_class->expose_event = geany_wrap_label_expose;
  89 #endif
  90
  91         g_type_class_add_private(klass, sizeof (GeanyWrapLabelPrivate));
  92 }
  93
  94
  95 static void geany_wrap_label_init(GeanyWrapLabel *self)
  96 {
  97         self->priv = G_TYPE_INSTANCE_GET_PRIVATE(self,
  98                 GEANY_WRAP_LABEL_TYPE, GeanyWrapLabelPrivate);
  99
 100         self->priv->wrap_width = 0;
 101         self->priv->wrap_height = 0;
 102
 103         g_signal_connect(self, "notify::label", G_CALLBACK(geany_wrap_label_label_notify), NULL);
 104         gtk_misc_set_alignment(GTK_MISC(self), 0.0, 0.0);
 105 }
 106
 107
 108 /* Sets the point at which the text should wrap. */
 109 static void geany_wrap_label_set_wrap_width(GtkWidget *widget, gint width)
 110 {
 111         GeanyWrapLabel *self = GEANY_WRAP_LABEL(widget);
 112         PangoLayout *layout;
 113
 114         if (width <= 0)
 115                 return;
 116
 117         layout = gtk_label_get_layout(GTK_LABEL(widget));
 118
 119         /*
 120         * We may need to reset the wrap width, so do this regardless of whether
 121         * or not we've changed the width.
 122         */
 123         pango_layout_set_width(layout, width * PANGO_SCALE);
 124         pango_layout_set_wrap(layout, PANGO_WRAP_WORD_CHAR);
 125         pango_layout_get_pixel_size(layout, NULL, &self->priv->wrap_height);
 126
 127         if (self->priv->wrap_width != width)
 128         {
 129                 self->priv->wrap_width = width;
 130                 gtk_widget_queue_resize(widget);
 131         }
 132 }
 133
 134
 135 /* updates the wrap width when the label text changes */
 136 static void geany_wrap_label_label_notify(GObject *object, GParamSpec *pspec, gpointer data)
 137 {
 138         GeanyWrapLabel *self = GEANY_WRAP_LABEL(object);
 139
 140         geany_wrap_label_set_wrap_width(GTK_WIDGET(object), self->priv->wrap_width);
 141 }
 142
 143
 144 #if GTK_CHECK_VERSION(3, 0, 0)
 145 /* makes sure the layout is setup for rendering and chains to parent renderer */
 146 static gboolean geany_wrap_label_draw(GtkWidget *widget, cairo_t *cr)
 147 {
 148         GeanyWrapLabel *self = GEANY_WRAP_LABEL(widget);
 149         PangoLayout *layout = gtk_label_get_layout(GTK_LABEL(widget));
 150
 151         pango_layout_set_width(layout, self->priv->wrap_width * PANGO_SCALE);
 152         pango_layout_set_wrap(layout, PANGO_WRAP_WORD_CHAR);
 153
 154         return (* GTK_WIDGET_CLASS(geany_wrap_label_parent_class)->draw)(widget, cr);
 155 }
 156
 157
 158 static void geany_wrap_label_get_preferred_width (GtkWidget *widget,
 159                 gint *minimal_width, gint *natural_width)
 160 {
 161         *minimal_width = *natural_width = 0;
 162 }
 163
 164
 165 static void geany_wrap_label_get_preferred_width_for_height (GtkWidget *widget,
 166                 gint height, gint *minimal_width, gint *natural_width)
 167 {
 168         PangoLayout *layout = gtk_label_get_layout(GTK_LABEL(widget));;
 169
 170         pango_layout_set_height(layout, height * PANGO_SCALE);
 171         pango_layout_set_wrap(layout, PANGO_WRAP_WORD_CHAR);
 172         pango_layout_get_pixel_size(layout, natural_width, NULL);
 173
 174         *minimal_width = 0;
 175 }
 176
 177
 178 static void geany_wrap_label_get_preferred_height (GtkWidget *widget,
 179                 gint *minimal_height, gint *natural_height)
 180 {
 181         *minimal_height = *natural_height = GEANY_WRAP_LABEL(widget)->priv->wrap_height;
 182 }
 183
 184
 185 static void geany_wrap_label_get_preferred_height_for_width (GtkWidget *widget,
 186                 gint width, gint *minimal_height, gint *natural_height)
 187 {
 188         PangoLayout *layout = gtk_label_get_layout(GTK_LABEL(widget));
 189
 190         pango_layout_set_width(layout, width * PANGO_SCALE);
 191         pango_layout_set_wrap(layout, PANGO_WRAP_WORD_CHAR);
 192         pango_layout_get_pixel_size(layout, NULL, natural_height);
 193
 194         *minimal_height = *natural_height;
 195 }
 196
 197
 198 static GtkSizeRequestMode geany_wrap_label_get_request_mode(GtkWidget *widget)
 199 {
 200         return GTK_SIZE_REQUEST_WIDTH_FOR_HEIGHT;
 201 }
 202
 203 #else /* GTK3 */
 204
 205 /* makes sure the layout is setup for rendering and chains to parent renderer */
 206 static gboolean geany_wrap_label_expose(GtkWidget *widget, GdkEventExpose *event)
 207 {
 208         GeanyWrapLabel *self = GEANY_WRAP_LABEL(widget);
 209         PangoLayout *layout = gtk_label_get_layout(GTK_LABEL(widget));
 210
 211         pango_layout_set_width(layout, self->priv->wrap_width * PANGO_SCALE);
 212         pango_layout_set_wrap(layout, PANGO_WRAP_WORD_CHAR);
 213
 214         return (* GTK_WIDGET_CLASS(geany_wrap_label_parent_class)->expose_event)(widget, event);
 215 }
 216
 217
 218 /* Forces the height to be the size necessary for the Pango layout, while allowing the
 219  * width to be flexible. */
 220 static void geany_wrap_label_size_request(GtkWidget *widget, GtkRequisition *req)
 221 {
 222         req->width = 0;
 223         req->height = GEANY_WRAP_LABEL(widget)->priv->wrap_height;
 224 }
 225 #endif /* GTK3 */
 226
 227
 228 /* Sets the wrap width to the width allocated to us. */
 229 static void geany_wrap_label_size_allocate(GtkWidget *widget, GtkAllocation *alloc)
 230 {
 231         (* GTK_WIDGET_CLASS(geany_wrap_label_parent_class)->size_allocate)(widget, alloc);
 232
 233         geany_wrap_label_set_wrap_width(widget, alloc->width);
 234
 235 #if GTK_CHECK_VERSION(3, 0, 0)
 236 {
 237         /* ask the parent to recompute our size, because it seems GTK3 size
 238          * caching is too aggressive */
 239         GtkWidget *parent = gtk_widget_get_parent(widget);
 240         if (GTK_IS_CONTAINER(parent))
 241                 gtk_container_check_resize(GTK_CONTAINER(parent));
 242 }
 243 #endif
 244 }
 245
 246
 247 GtkWidget *geany_wrap_label_new(const gchar *text)
 248 {
 249         return g_object_new(GEANY_WRAP_LABEL_TYPE, "label", text, NULL);
 250 }