diff options
Diffstat (limited to 'demos/gtk-demo/simplelabel.c')
| -rw-r--r-- | demos/gtk-demo/simplelabel.c | 260 |
1 files changed, 260 insertions, 0 deletions
diff --git a/demos/gtk-demo/simplelabel.c b/demos/gtk-demo/simplelabel.c new file mode 100644 index 0000000000..ada2848c33 --- /dev/null +++ b/demos/gtk-demo/simplelabel.c @@ -0,0 +1,260 @@ +#include "simplelabel.h" + +struct _SimpleLabel +{ + GtkWidget parent_instance; + + PangoLayout *layout; + int min_chars; + int nat_chars; + + int min_width; + int nat_width; + int height; +}; + +struct _SimpleLabelClass +{ + GtkWidgetClass parent_class; +}; + +enum { + PROP_TEXT = 1, + PROP_MIN_CHARS, + PROP_NAT_CHARS, + NUM_PROPERTIES +}; + +static GParamSpec *properties[NUM_PROPERTIES] = { NULL, }; + +G_DEFINE_TYPE (SimpleLabel, simple_label, GTK_TYPE_WIDGET) + +static void +simple_label_init (SimpleLabel *self) +{ + self->layout = gtk_widget_create_pango_layout (GTK_WIDGET (self), ""); + pango_layout_set_ellipsize (self->layout, PANGO_ELLIPSIZE_NONE); + pango_layout_set_wrap (self->layout, PANGO_WRAP_WORD); + pango_layout_set_width (self->layout, -1); +} + +static void +simple_label_dispose (GObject *object) +{ + SimpleLabel *self = SIMPLE_LABEL (object); + + g_clear_object (&self->layout); + + G_OBJECT_CLASS (simple_label_parent_class)->dispose (object); +} + +static void +simple_label_set_property (GObject *object, + guint prop_id, + const GValue *value, + GParamSpec *pspec) +{ + SimpleLabel *self = SIMPLE_LABEL (object); + + switch (prop_id) + { + case PROP_TEXT: + simple_label_set_text (self, g_value_get_string (value)); + break; + + case PROP_MIN_CHARS: + simple_label_set_min_chars (self, g_value_get_int (value)); + break; + + case PROP_NAT_CHARS: + simple_label_set_nat_chars (self, g_value_get_int (value)); + break; + + default: + G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, pspec); + break; + } +} + +static void +simple_label_get_property (GObject *object, + guint prop_id, + GValue *value, + GParamSpec *pspec) +{ + SimpleLabel *self = SIMPLE_LABEL (object); + + switch (prop_id) + { + case PROP_TEXT: + g_value_set_string (value, pango_layout_get_text (self->layout)); + break; + + case PROP_MIN_CHARS: + g_value_set_int (value, self->min_chars); + break; + + case PROP_NAT_CHARS: + g_value_set_int (value, self->nat_chars); + break; + + default: + G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, pspec); + break; + } +} + +static void +simple_label_measure (GtkWidget *widget, + GtkOrientation orientation, + int for_size, + int *minimum, + int *natural, + int *minimum_baseline, + int *natural_baseline) +{ + SimpleLabel *self = SIMPLE_LABEL (widget); + + if (orientation == GTK_ORIENTATION_VERTICAL) + { + *minimum = *natural = self->height; + } + else + { + *minimum = self->min_width; + *natural = self->nat_width; + } +} + +static void +simple_label_size_allocate (GtkWidget *widget, + int width, + int height, + int baseline) +{ + SimpleLabel *self = SIMPLE_LABEL (widget); + + pango_layout_set_width (self->layout, width * PANGO_SCALE); +} + +static void +simple_label_snapshot (GtkWidget *widget, + GtkSnapshot *snapshot) +{ + SimpleLabel *self = SIMPLE_LABEL (widget); + GtkStyleContext *context; + + context = gtk_widget_get_style_context (widget); + + gtk_snapshot_render_layout (snapshot, context, 0, 0, self->layout); +} + +static void +simple_label_class_init (SimpleLabelClass *class) +{ + GObjectClass *object_class = G_OBJECT_CLASS (class); + GtkWidgetClass *widget_class = GTK_WIDGET_CLASS (class); + + object_class->dispose = simple_label_dispose; + object_class->set_property = simple_label_set_property; + object_class->get_property = simple_label_get_property; + + widget_class->measure = simple_label_measure; + widget_class->size_allocate = simple_label_size_allocate; + widget_class->snapshot = simple_label_snapshot; + + properties[PROP_TEXT] = + g_param_spec_string ("text", "Text", "Text", + NULL, + G_PARAM_READWRITE); + + properties[PROP_MIN_CHARS] = + g_param_spec_int ("min-chars", "Minimum Characters", "Minimum Characters", + 0, G_MAXINT, 0, + G_PARAM_READWRITE); + + properties[PROP_NAT_CHARS] = + g_param_spec_int ("nat-chars", "Natural Characters", "Natural Characters", + 0, G_MAXINT, 0, + G_PARAM_READWRITE); + + g_object_class_install_properties (object_class, NUM_PROPERTIES, properties); +} + +GtkWidget * +simple_label_new (void) +{ + return g_object_new (SIMPLE_TYPE_LABEL, NULL); +} + +void +simple_label_set_text (SimpleLabel *self, + const char *text) +{ + if (strcmp (text, pango_layout_get_text (self->layout)) == 0) + return; + + pango_layout_set_text (self->layout, text, -1); + + gtk_widget_queue_draw (GTK_WIDGET (self)); + + g_object_notify_by_pspec (G_OBJECT (self), properties[PROP_TEXT]); +} + +static void +recalculate (SimpleLabel *self) +{ + PangoContext *context; + PangoFontMetrics *metrics; + int char_width; + int digit_width; + int width; + int ascent; + int descent; + + context = gtk_widget_get_pango_context (GTK_WIDGET (self)); + metrics = pango_context_get_metrics (context, + pango_context_get_font_description (context), + pango_context_get_language (context)); + char_width = pango_font_metrics_get_approximate_char_width (metrics); + digit_width = pango_font_metrics_get_approximate_digit_width (metrics); + ascent = pango_font_metrics_get_ascent (metrics); + descent = pango_font_metrics_get_descent (metrics); + pango_font_metrics_unref (metrics); + + width = MAX (char_width, digit_width); + + self->min_width = (width * self->min_chars) / PANGO_SCALE; + self->nat_width = (width * self->nat_chars) / PANGO_SCALE; + self->height = (ascent + descent) / PANGO_SCALE; +} + +void +simple_label_set_min_chars (SimpleLabel *self, + int min_chars) +{ + if (self->min_chars == min_chars) + return; + + self->min_chars = min_chars; + + recalculate (self); + gtk_widget_queue_resize (GTK_WIDGET (self)); + + g_object_notify_by_pspec (G_OBJECT (self), properties[PROP_MIN_CHARS]); +} + +void +simple_label_set_nat_chars (SimpleLabel *self, + int nat_chars) +{ + if (self->nat_chars == nat_chars) + return; + + self->nat_chars = nat_chars; + + recalculate (self); + gtk_widget_queue_resize (GTK_WIDGET (self)); + + g_object_notify_by_pspec (G_OBJECT (self), properties[PROP_NAT_CHARS]); +} |