Center zoom around pointer or middle of the view

This commit is contained in:
Přemysl Eric Janouch 2022-07-17 08:50:11 +02:00
parent 4efda5347c
commit 8f98c623ee
Signed by: p
GPG Key ID: A0420B94F92B9493
1 changed files with 53 additions and 16 deletions

View File

@ -543,9 +543,9 @@ fiv_view_draw(GtkWidget *widget, cairo_t *cr)
double x = 0; double x = 0;
double y = 0; double y = 0;
if (self->hadjustment) if (self->hadjustment)
x = -gtk_adjustment_get_value(self->hadjustment); x = -floor(gtk_adjustment_get_value(self->hadjustment));
if (self->vadjustment) if (self->vadjustment)
y = -gtk_adjustment_get_value(self->vadjustment); y = -floor(gtk_adjustment_get_value(self->vadjustment));
if (w < allocation.width) if (w < allocation.width)
x = round((allocation.width - w) / 2.); x = round((allocation.width - w) / 2.);
if (h < allocation.height) if (h < allocation.height)
@ -645,15 +645,52 @@ set_scale_to_fit(FivView *self, bool scale_to_fit)
} }
static gboolean static gboolean
set_scale(FivView *self, double scale) set_scale(FivView *self, double scale, const GdkEvent *event)
{ {
if (self->scale != scale) { if (self->scale == scale)
self->scale = scale; goto out;
g_object_notify_by_pspec(G_OBJECT(self), view_properties[PROP_SCALE]);
prescale_page(self);
gtk_widget_queue_resize(GTK_WIDGET(self)); GtkAllocation allocation;
gtk_widget_get_allocation(GTK_WIDGET(self), &allocation);
double focus_x = 0, focus_y = 0, surface_x = 0, surface_y = 0;
if (!event || !gdk_event_get_coords(event, &focus_x, &focus_y)) {
focus_x = 0.5 * allocation.width;
focus_y = 0.5 * allocation.height;
} }
if (self->hadjustment && self->vadjustment) {
int w, h;
get_display_dimensions(self, &w, &h);
surface_x = (focus_x + (w < allocation.width
? -round((allocation.width - w) / 2.)
: +floor(gtk_adjustment_get_value(self->hadjustment))))
/ self->scale;
surface_y = (focus_y + (h < allocation.height
? -round((allocation.height - h) / 2.)
: +floor(gtk_adjustment_get_value(self->vadjustment))))
/ self->scale;
}
self->scale = scale;
g_object_notify_by_pspec(G_OBJECT(self), view_properties[PROP_SCALE]);
prescale_page(self);
if (self->hadjustment && self->vadjustment) {
update_adjustments(self);
Dimensions surface_dimensions = get_surface_dimensions(self);
if (surface_dimensions.width * self->scale > allocation.width)
gtk_adjustment_set_value(
self->hadjustment, surface_x * self->scale - focus_x);
if (surface_dimensions.height * self->scale > allocation.height)
gtk_adjustment_set_value(
self->vadjustment, surface_y * self->scale - focus_y);
}
gtk_widget_queue_resize(GTK_WIDGET(self));
out:
return set_scale_to_fit(self, false); return set_scale_to_fit(self, false);
} }
@ -663,7 +700,7 @@ set_scale_to_fit_width(FivView *self)
double w = get_surface_dimensions(self).width; double w = get_surface_dimensions(self).width;
int allocated = gtk_widget_get_allocated_width(GTK_WIDGET(self)); int allocated = gtk_widget_get_allocated_width(GTK_WIDGET(self));
if (ceil(w * self->scale) > allocated) if (ceil(w * self->scale) > allocated)
set_scale(self, allocated / w); set_scale(self, allocated / w, NULL);
} }
static void static void
@ -672,7 +709,7 @@ set_scale_to_fit_height(FivView *self)
double h = get_surface_dimensions(self).height; double h = get_surface_dimensions(self).height;
int allocated = gtk_widget_get_allocated_height(GTK_WIDGET(self)); int allocated = gtk_widget_get_allocated_height(GTK_WIDGET(self));
if (ceil(h * self->scale) > allocated) if (ceil(h * self->scale) > allocated)
set_scale(self, allocated / h); set_scale(self, allocated / h, NULL);
} }
static gboolean static gboolean
@ -686,9 +723,9 @@ fiv_view_scroll_event(GtkWidget *widget, GdkEventScroll *event)
switch (event->direction) { switch (event->direction) {
case GDK_SCROLL_UP: case GDK_SCROLL_UP:
return set_scale(self, self->scale * SCALE_STEP); return set_scale(self, self->scale * SCALE_STEP, (GdkEvent *) event);
case GDK_SCROLL_DOWN: case GDK_SCROLL_DOWN:
return set_scale(self, self->scale / SCALE_STEP); return set_scale(self, self->scale / SCALE_STEP, (GdkEvent *) event);
default: default:
// For some reason, native GdkWindows may also get GDK_SCROLL_SMOOTH. // For some reason, native GdkWindows may also get GDK_SCROLL_SMOOTH.
// Left/right are good to steal from GtkScrolledWindow for consistency. // Left/right are good to steal from GtkScrolledWindow for consistency.
@ -1196,7 +1233,7 @@ fiv_view_key_press_event(GtkWidget *widget, GdkEventKey *event)
if (self->image && if (self->image &&
!(event->state & gtk_accelerator_get_default_mod_mask()) && !(event->state & gtk_accelerator_get_default_mod_mask()) &&
event->keyval >= GDK_KEY_1 && event->keyval <= GDK_KEY_9) event->keyval >= GDK_KEY_1 && event->keyval <= GDK_KEY_9)
return set_scale(self, event->keyval - GDK_KEY_0); return set_scale(self, event->keyval - GDK_KEY_0, NULL);
return GTK_WIDGET_CLASS(fiv_view_parent_class) return GTK_WIDGET_CLASS(fiv_view_parent_class)
->key_press_event(widget, event); ->key_press_event(widget, event);
@ -1538,11 +1575,11 @@ fiv_view_command(FivView *self, FivViewCommand command)
info(self); info(self);
break; case FIV_VIEW_COMMAND_ZOOM_IN: break; case FIV_VIEW_COMMAND_ZOOM_IN:
set_scale(self, self->scale * SCALE_STEP); set_scale(self, self->scale * SCALE_STEP, NULL);
break; case FIV_VIEW_COMMAND_ZOOM_OUT: break; case FIV_VIEW_COMMAND_ZOOM_OUT:
set_scale(self, self->scale / SCALE_STEP); set_scale(self, self->scale / SCALE_STEP, NULL);
break; case FIV_VIEW_COMMAND_ZOOM_1: break; case FIV_VIEW_COMMAND_ZOOM_1:
set_scale(self, 1.0); set_scale(self, 1.0, NULL);
break; case FIV_VIEW_COMMAND_FIT_WIDTH: break; case FIV_VIEW_COMMAND_FIT_WIDTH:
set_scale_to_fit_width(self); set_scale_to_fit_width(self);
break; case FIV_VIEW_COMMAND_FIT_HEIGHT: break; case FIV_VIEW_COMMAND_FIT_HEIGHT: