Learning_GTK4_tree/demos/gtk-demo/path_text.c

585 lines
17 KiB
C

/* Path/Text
*
* This demo shows how to use GskPath to transform a path along another path.
*
* It also demonstrates that paths can be filled with more interesting
* content than just plain colors.
*/
#include <glib/gi18n.h>
#include <gtk/gtk.h>
#define GTK_TYPE_PATH_WIDGET (gtk_path_widget_get_type ())
G_DECLARE_FINAL_TYPE (GtkPathWidget, gtk_path_widget, GTK, PATH_WIDGET, GtkWidget)
#define POINT_SIZE 8
enum {
PROP_0,
PROP_TEXT,
PROP_EDITABLE,
N_PROPS
};
struct _GtkPathWidget
{
GtkWidget parent_instance;
char *text;
gboolean editable;
graphene_point_t points[4];
guint active_point;
GskPath *line_path;
GskPath *text_path;
GdkPaintable *background;
};
struct _GtkPathWidgetClass
{
GtkWidgetClass parent_class;
};
static GParamSpec *properties[N_PROPS] = { NULL, };
G_DEFINE_TYPE (GtkPathWidget, gtk_path_widget, GTK_TYPE_WIDGET)
static GskPath *
create_path_from_text (GtkWidget *widget,
const char *text,
graphene_point_t *out_offset)
{
PangoLayout *layout;
PangoFontDescription *desc;
GskPathBuilder *builder;
GskPath *result;
layout = gtk_widget_create_pango_layout (widget, text);
desc = pango_font_description_from_string ("sans bold 36");
pango_layout_set_font_description (layout, desc);
pango_font_description_free (desc);
builder = gsk_path_builder_new ();
gsk_path_builder_add_layout (builder, layout);
result = gsk_path_builder_free_to_path (builder);
if (out_offset)
graphene_point_init (out_offset, 0, - pango_layout_get_baseline (layout) / (double) PANGO_SCALE);
g_object_unref (layout);
return result;
}
typedef struct
{
GskPathMeasure *measure;
GskPathBuilder *builder;
graphene_point_t offset;
double scale;
} GtkPathTransform;
static void
gtk_path_transform_point (GskPathMeasure *measure,
const graphene_point_t *pt,
const graphene_point_t *offset,
float scale,
graphene_point_t *res)
{
graphene_vec2_t tangent;
GskPathPoint point;
if (gsk_path_measure_get_point (measure, (pt->x + offset->x) * scale, &point))
{
GskPath *path = gsk_path_measure_get_path (measure);
gsk_path_point_get_position (&point, path, res);
gsk_path_point_get_tangent (&point, path, GSK_PATH_TO_END, &tangent);
res->x -= (pt->y + offset->y) * scale * graphene_vec2_get_y (&tangent);
res->y += (pt->y + offset->y) * scale * graphene_vec2_get_x (&tangent);
}
}
static gboolean
gtk_path_transform_op (GskPathOperation op,
const graphene_point_t *pts,
gsize n_pts,
float weight,
gpointer data)
{
GtkPathTransform *transform = data;
switch (op)
{
case GSK_PATH_MOVE:
{
graphene_point_t res;
gtk_path_transform_point (transform->measure, &pts[0], &transform->offset, transform->scale, &res);
gsk_path_builder_move_to (transform->builder, res.x, res.y);
}
break;
case GSK_PATH_LINE:
{
graphene_point_t res;
gtk_path_transform_point (transform->measure, &pts[1], &transform->offset, transform->scale, &res);
gsk_path_builder_line_to (transform->builder, res.x, res.y);
}
break;
case GSK_PATH_QUAD:
{
graphene_point_t res[2];
gtk_path_transform_point (transform->measure, &pts[1], &transform->offset, transform->scale, &res[0]);
gtk_path_transform_point (transform->measure, &pts[2], &transform->offset, transform->scale, &res[1]);
gsk_path_builder_quad_to (transform->builder, res[0].x, res[0].y, res[1].x, res[1].y);
}
break;
case GSK_PATH_CUBIC:
{
graphene_point_t res[3];
gtk_path_transform_point (transform->measure, &pts[1], &transform->offset, transform->scale, &res[0]);
gtk_path_transform_point (transform->measure, &pts[2], &transform->offset, transform->scale, &res[1]);
gtk_path_transform_point (transform->measure, &pts[3], &transform->offset, transform->scale, &res[2]);
gsk_path_builder_cubic_to (transform->builder, res[0].x, res[0].y, res[1].x, res[1].y, res[2].x, res[2].y);
}
break;
case GSK_PATH_CONIC:
{
graphene_point_t res[2];
gtk_path_transform_point (transform->measure, &pts[1], &transform->offset, transform->scale, &res[0]);
gtk_path_transform_point (transform->measure, &pts[3], &transform->offset, transform->scale, &res[1]);
gsk_path_builder_conic_to (transform->builder, res[0].x, res[0].y, res[1].x, res[1].y, weight);
}
break;
case GSK_PATH_CLOSE:
gsk_path_builder_close (transform->builder);
break;
default:
g_assert_not_reached();
return FALSE;
}
return TRUE;
}
static GskPath *
gtk_path_transform (GskPath *line_path,
GskPath *path,
const graphene_point_t *offset)
{
GskPathMeasure *measure = gsk_path_measure_new (line_path);
GtkPathTransform transform = { measure, gsk_path_builder_new (), *offset };
graphene_rect_t bounds;
gsk_path_get_bounds (path, &bounds);
if (bounds.origin.x + bounds.size.width > 0)
transform.scale = gsk_path_measure_get_length (measure) / (bounds.origin.x + bounds.size.width);
else
transform.scale = 1.0f;
gsk_path_foreach (path, -1, gtk_path_transform_op, &transform);
gsk_path_measure_unref (measure);
return gsk_path_builder_free_to_path (transform.builder);
}
static void
gtk_path_widget_clear_text_path (GtkPathWidget *self)
{
g_clear_pointer (&self->text_path, gsk_path_unref);
}
static void
gtk_path_widget_clear_paths (GtkPathWidget *self)
{
gtk_path_widget_clear_text_path (self);
g_clear_pointer (&self->line_path, gsk_path_unref);
}
static void
gtk_path_widget_create_text_path (GtkPathWidget *self)
{
GskPath *path;
graphene_point_t offset;
gtk_path_widget_clear_text_path (self);
path = create_path_from_text (GTK_WIDGET (self), self->text, &offset);
self->text_path = gtk_path_transform (self->line_path, path, &offset);
gsk_path_unref (path);
}
static void
gtk_path_widget_create_paths (GtkPathWidget *self)
{
double width = gtk_widget_get_width (GTK_WIDGET (self));
double height = gtk_widget_get_height (GTK_WIDGET (self));
GskPathBuilder *builder;
gtk_path_widget_clear_paths (self);
if (width <= 0 || height <= 0)
return;
builder = gsk_path_builder_new ();
gsk_path_builder_move_to (builder,
self->points[0].x * width, self->points[0].y * height);
gsk_path_builder_cubic_to (builder,
self->points[1].x * width, self->points[1].y * height,
self->points[2].x * width, self->points[2].y * height,
self->points[3].x * width, self->points[3].y * height);
self->line_path = gsk_path_builder_free_to_path (builder);
gtk_path_widget_create_text_path (self);
}
static void
gtk_path_widget_allocate (GtkWidget *widget,
int width,
int height,
int baseline)
{
GtkPathWidget *self = GTK_PATH_WIDGET (widget);
GTK_WIDGET_CLASS (gtk_path_widget_parent_class)->size_allocate (widget, width, height, baseline);
gtk_path_widget_create_paths (self);
}
static void
gtk_path_widget_snapshot (GtkWidget *widget,
GtkSnapshot *snapshot)
{
GtkPathWidget *self = GTK_PATH_WIDGET (widget);
double width = gtk_widget_get_width (widget);
double height = gtk_widget_get_height (widget);
GskPath *path;
GskStroke *stroke;
gsize i;
/* frosted glass the background */
gtk_snapshot_push_blur (snapshot, 100);
gdk_paintable_snapshot (self->background, snapshot, width, height);
gtk_snapshot_append_color (snapshot, &(GdkRGBA) { 1, 1, 1, 0.6 }, &GRAPHENE_RECT_INIT (0, 0, width, height));
gtk_snapshot_pop (snapshot);
/* draw the text */
if (self->text_path)
{
gtk_snapshot_push_fill (snapshot, self->text_path, GSK_FILL_RULE_WINDING);
gdk_paintable_snapshot (self->background, snapshot, width, height);
/* ... with an emboss effect */
stroke = gsk_stroke_new (2.0);
gtk_snapshot_translate (snapshot, &GRAPHENE_POINT_INIT(1, 1));
gtk_snapshot_push_stroke (snapshot, self->text_path, stroke);
gtk_snapshot_append_color (snapshot, &(GdkRGBA) { 0, 0, 0, 0.2 }, &GRAPHENE_RECT_INIT (0, 0, width, height));
gsk_stroke_free (stroke);
gtk_snapshot_pop (snapshot);
gtk_snapshot_pop (snapshot);
}
if (self->editable && self->line_path)
{
GskPathBuilder *builder;
/* draw the control line */
stroke = gsk_stroke_new (1.0);
gtk_snapshot_push_stroke (snapshot, self->line_path, stroke);
gsk_stroke_free (stroke);
gtk_snapshot_append_color (snapshot, &(GdkRGBA) { 0, 0, 0, 1 }, &GRAPHENE_RECT_INIT (0, 0, width, height));
gtk_snapshot_pop (snapshot);
/* draw the points */
builder = gsk_path_builder_new ();
for (i = 0; i < 4; i++)
{
gsk_path_builder_add_circle (builder, &GRAPHENE_POINT_INIT (self->points[i].x * width, self->points[i].y * height), POINT_SIZE);
}
path = gsk_path_builder_free_to_path (builder);
gtk_snapshot_push_fill (snapshot, path, GSK_FILL_RULE_WINDING);
gtk_snapshot_append_color (snapshot, &(GdkRGBA) { 1, 1, 1, 1 }, &GRAPHENE_RECT_INIT (0, 0, width, height));
gtk_snapshot_pop (snapshot);
stroke = gsk_stroke_new (1.0);
gtk_snapshot_push_stroke (snapshot, path, stroke);
gsk_stroke_free (stroke);
gtk_snapshot_append_color (snapshot, &(GdkRGBA) { 0, 0, 0, 1 }, &GRAPHENE_RECT_INIT (0, 0, width, height));
gtk_snapshot_pop (snapshot);
gsk_path_unref (path);
}
}
static void
gtk_path_widget_set_text (GtkPathWidget *self,
const char *text)
{
if (g_strcmp0 (self->text, text) == 0)
return;
g_free (self->text);
self->text = g_strdup (text);
gtk_path_widget_create_paths (self);
gtk_widget_queue_draw (GTK_WIDGET (self));
g_object_notify_by_pspec (G_OBJECT (self), properties[PROP_TEXT]);
}
static void
gtk_path_widget_set_editable (GtkPathWidget *self,
gboolean editable)
{
if (self->editable == editable)
return;
self->editable = editable;
gtk_widget_queue_draw (GTK_WIDGET (self));
g_object_notify_by_pspec (G_OBJECT (self), properties[PROP_EDITABLE]);
}
static void
gtk_path_widget_set_property (GObject *object,
guint prop_id,
const GValue *value,
GParamSpec *pspec)
{
GtkPathWidget *self = GTK_PATH_WIDGET (object);
switch (prop_id)
{
case PROP_TEXT:
gtk_path_widget_set_text (self, g_value_get_string (value));
break;
case PROP_EDITABLE:
gtk_path_widget_set_editable (self, g_value_get_boolean (value));
break;
default:
G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, pspec);
break;
}
}
static void
gtk_path_widget_get_property (GObject *object,
guint prop_id,
GValue *value,
GParamSpec *pspec)
{
GtkPathWidget *self = GTK_PATH_WIDGET (object);
switch (prop_id)
{
case PROP_TEXT:
g_value_set_string (value, self->text);
break;
case PROP_EDITABLE:
g_value_set_boolean (value, self->editable);
break;
default:
G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, pspec);
break;
}
}
static void
gtk_path_widget_dispose (GObject *object)
{
GtkPathWidget *self = GTK_PATH_WIDGET (object);
gtk_path_widget_clear_paths (self);
G_OBJECT_CLASS (gtk_path_widget_parent_class)->dispose (object);
}
static void
gtk_path_widget_class_init (GtkPathWidgetClass *klass)
{
GtkWidgetClass *widget_class = GTK_WIDGET_CLASS (klass);
GObjectClass *object_class = G_OBJECT_CLASS (klass);
object_class->dispose = gtk_path_widget_dispose;
object_class->set_property = gtk_path_widget_set_property;
object_class->get_property = gtk_path_widget_get_property;
widget_class->size_allocate = gtk_path_widget_allocate;
widget_class->snapshot = gtk_path_widget_snapshot;
properties[PROP_TEXT] =
g_param_spec_string ("text",
"text",
"Text transformed along a path",
NULL,
G_PARAM_READWRITE | G_PARAM_EXPLICIT_NOTIFY | G_PARAM_STATIC_STRINGS);
properties[PROP_EDITABLE] =
g_param_spec_boolean ("editable",
"editable",
"If the path can be edited by the user",
FALSE,
G_PARAM_READWRITE | G_PARAM_EXPLICIT_NOTIFY | G_PARAM_STATIC_STRINGS);
g_object_class_install_properties (object_class, N_PROPS, properties);
}
static void
drag_begin (GtkGestureDrag *gesture,
double x,
double y,
GtkPathWidget *self)
{
graphene_point_t mouse = GRAPHENE_POINT_INIT (x, y);
double width = gtk_widget_get_width (GTK_WIDGET (self));
double height = gtk_widget_get_height (GTK_WIDGET (self));
gsize i;
for (i = 0; i < 4; i++)
{
if (graphene_point_distance (&GRAPHENE_POINT_INIT (self->points[i].x * width, self->points[i].y * height), &mouse, NULL, NULL) <= POINT_SIZE)
{
self->active_point = i;
break;
}
}
if (i == 4)
{
gtk_gesture_set_state (GTK_GESTURE (gesture), GTK_EVENT_SEQUENCE_DENIED);
return;
}
gtk_widget_queue_draw (GTK_WIDGET (self));
}
static void
drag_update (GtkGestureDrag *drag,
double offset_x,
double offset_y,
GtkPathWidget *self)
{
double width = gtk_widget_get_width (GTK_WIDGET (self));
double height = gtk_widget_get_height (GTK_WIDGET (self));
double start_x, start_y;
gtk_gesture_drag_get_start_point (drag, &start_x, &start_y);
self->points[self->active_point] = GRAPHENE_POINT_INIT ((start_x + offset_x) / width,
(start_y + offset_y) / height);
self->points[self->active_point].x = CLAMP (self->points[self->active_point].x, 0, 1);
self->points[self->active_point].y = CLAMP (self->points[self->active_point].y, 0, 1);
gtk_path_widget_create_paths (self);
gtk_widget_queue_draw (GTK_WIDGET (self));
}
static void
pointer_motion (GtkEventControllerMotion *controller,
double x,
double y,
GtkPathWidget *self)
{
GskPathPoint point;
if (gsk_path_get_closest_point (self->line_path,
&GRAPHENE_POINT_INIT (x, y),
INFINITY,
&point,
NULL))
{
gtk_widget_queue_draw (GTK_WIDGET (self));
}
}
static void
pointer_leave (GtkEventControllerMotion *controller,
GtkPathWidget *self)
{
gtk_widget_queue_draw (GTK_WIDGET (self));
}
static void
gtk_path_widget_init (GtkPathWidget *self)
{
GtkEventController *controller;
controller = GTK_EVENT_CONTROLLER (gtk_gesture_drag_new ());
g_signal_connect (controller, "drag-begin", G_CALLBACK (drag_begin), self);
g_signal_connect (controller, "drag-update", G_CALLBACK (drag_update), self);
g_signal_connect (controller, "drag-end", G_CALLBACK (drag_update), self);
gtk_widget_add_controller (GTK_WIDGET (self), controller);
controller = GTK_EVENT_CONTROLLER (gtk_event_controller_motion_new ());
g_signal_connect (controller, "enter", G_CALLBACK (pointer_motion), self);
g_signal_connect (controller, "motion", G_CALLBACK (pointer_motion), self);
g_signal_connect (controller, "leave", G_CALLBACK (pointer_leave), self);
gtk_widget_add_controller (GTK_WIDGET (self), controller);
self->points[0] = GRAPHENE_POINT_INIT (0.1, 0.9);
self->points[1] = GRAPHENE_POINT_INIT (0.3, 0.1);
self->points[2] = GRAPHENE_POINT_INIT (0.7, 0.1);
self->points[3] = GRAPHENE_POINT_INIT (0.9, 0.9);
self->background = GDK_PAINTABLE (gdk_texture_new_from_resource ("/sliding_puzzle/portland-rose.jpg"));
gtk_path_widget_set_text (self, "It's almost working");
}
GtkWidget *
gtk_path_widget_new (void)
{
GtkPathWidget *self;
self = g_object_new (GTK_TYPE_PATH_WIDGET, NULL);
return GTK_WIDGET (self);
}
GtkWidget *
do_path_text (GtkWidget *do_widget)
{
static GtkWidget *window = NULL;
if (!window)
{
GtkBuilder *builder;
g_type_ensure (GTK_TYPE_PATH_WIDGET);
builder = gtk_builder_new_from_resource ("/path_text/path_text.ui");
window = GTK_WIDGET (gtk_builder_get_object (builder, "window"));
gtk_window_set_display (GTK_WINDOW (window),
gtk_widget_get_display (do_widget));
g_object_add_weak_pointer (G_OBJECT (window), (gpointer *) &window);
g_object_unref (builder);
}
if (!gtk_widget_get_visible (window))
gtk_window_present (GTK_WINDOW (window));
else
gtk_window_destroy (GTK_WINDOW (window));
return window;
}