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//
// fastiv-view.c: fast image viewer - view widget
//
// Copyright (c) 2021, Přemysl Eric Janouch <p@janouch.name>
//
// Permission to use, copy, modify, and/or distribute this software for any
// purpose with or without fee is hereby granted.
//
// THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
// WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
// MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY
// SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
// WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION
// OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN
// CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
//
#include <math.h>
#include "fastiv-io.h"
#include "fastiv-view.h"
struct _FastivView {
GtkWidget parent_instance;
cairo_surface_t *surface;
// TODO(p): Zoom-to-fit indication.
double scale;
};
G_DEFINE_TYPE(FastivView, fastiv_view, GTK_TYPE_WIDGET)
static int
get_display_width(FastivView *self)
{
if (!self->surface)
return 0;
return ceil(cairo_image_surface_get_width(self->surface) * self->scale);
}
static int
get_display_height(FastivView *self)
{
if (!self->surface)
return 0;
return ceil(cairo_image_surface_get_height(self->surface) * self->scale);
}
static void
fastiv_view_finalize(GObject *gobject)
{
FastivView *self = FASTIV_VIEW(gobject);
cairo_surface_destroy(self->surface);
G_OBJECT_CLASS(fastiv_view_parent_class)->finalize(gobject);
}
static void
fastiv_view_get_preferred_height(GtkWidget *widget,
gint *minimum, gint *natural)
{
*minimum = 0;
*natural = 0;
FastivView *self = FASTIV_VIEW(widget);
*natural = get_display_height(self);
}
static void
fastiv_view_get_preferred_width(GtkWidget *widget,
gint *minimum, gint *natural)
{
*minimum = 0;
*natural = 0;
FastivView *self = FASTIV_VIEW(widget);
*natural = get_display_width(self);
}
static void
fastiv_view_realize(GtkWidget *widget)
{
GtkAllocation allocation;
gtk_widget_get_allocation(widget, &allocation);
GdkWindowAttr attributes = {
.window_type = GDK_WINDOW_CHILD,
.x = allocation.x,
.y = allocation.y,
.width = allocation.width,
.height = allocation.height,
// Input-only would presumably also work (as in GtkPathBar, e.g.),
// but it merely seems to involve more work.
.wclass = GDK_INPUT_OUTPUT,
// Assuming here that we can't ask for a higher-precision Visual
// than what we get automatically.
.visual = gtk_widget_get_visual(widget),
.event_mask = gtk_widget_get_events(widget) | GDK_SCROLL_MASK,
};
// We need this window to receive input events at all.
GdkWindow *window = gdk_window_new(gtk_widget_get_parent_window(widget),
&attributes, GDK_WA_X | GDK_WA_Y | GDK_WA_VISUAL);
gtk_widget_register_window(widget, window);
gtk_widget_set_window(widget, window);
gtk_widget_set_realized(widget, TRUE);
}
static gboolean
fastiv_view_draw(GtkWidget *widget, cairo_t *cr)
{
FastivView *self = FASTIV_VIEW(widget);
if (!self->surface
|| !gtk_cairo_should_draw_window(cr, gtk_widget_get_window(widget)))
return TRUE;
GtkAllocation allocation;
gtk_widget_get_allocation(widget, &allocation);
gtk_render_background(gtk_widget_get_style_context(widget), cr,
0, 0, allocation.width, allocation.height);
int w = get_display_width(self);
int h = get_display_height(self);
double x = 0;
double y = 0;
if (w < allocation.width)
x = round((allocation.width - w) / 2.);
if (h < allocation.height)
y = round((allocation.height - h) / 2.);
cairo_scale(cr, self->scale, self->scale);
cairo_set_source_surface(cr, self->surface,
x / self->scale, y / self->scale);
// TODO(p): Prescale it ourselves to an off-screen bitmap, gamma-correctly.
cairo_pattern_set_filter(cairo_get_source(cr), CAIRO_FILTER_GOOD);
cairo_paint(cr);
return TRUE;
}
static gboolean
fastiv_view_scroll_event(GtkWidget *widget, GdkEventScroll *event)
{
FastivView *self = FASTIV_VIEW(widget);
if (!self->surface)
return FALSE;
switch (event->direction) {
case GDK_SCROLL_UP:
self->scale *= 1.4;
gtk_widget_queue_resize(widget);
return TRUE;
case GDK_SCROLL_DOWN:
self->scale /= 1.4;
gtk_widget_queue_resize(widget);
return TRUE;
default:
return FALSE;
}
}
static void
fastiv_view_class_init(FastivViewClass *klass)
{
GObjectClass *object_class = G_OBJECT_CLASS(klass);
object_class->finalize = fastiv_view_finalize;
GtkWidgetClass *widget_class = GTK_WIDGET_CLASS(klass);
widget_class->get_preferred_height = fastiv_view_get_preferred_height;
widget_class->get_preferred_width = fastiv_view_get_preferred_width;
widget_class->realize = fastiv_view_realize;
widget_class->draw = fastiv_view_draw;
widget_class->scroll_event = fastiv_view_scroll_event;
// TODO(p): Later override "screen_changed", recreate Pango layouts there,
// if we get to have any, or otherwise reflect DPI changes.
gtk_widget_class_set_css_name(widget_class, "fastiv-view");
}
static void
fastiv_view_init(FastivView *self)
{
self->scale = 1.0;
}
// --- Picture loading ---------------------------------------------------------
// TODO(p): Progressive picture loading, or at least async/cancellable.
gboolean
fastiv_view_open(FastivView *self, const gchar *path, GError **error)
{
cairo_surface_t *surface = fastiv_io_open(path, error);
if (!surface)
return FALSE;
if (self->surface)
cairo_surface_destroy(self->surface);
self->surface = surface;
gtk_widget_queue_resize(GTK_WIDGET(self));
return TRUE;
}
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