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