From 8f98c623ee5601ab10607d0da9a1801351a66d45 Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?P=C5=99emysl=20Eric=20Janouch?= Date: Sun, 17 Jul 2022 08:50:11 +0200 Subject: Center zoom around pointer or middle of the view --- fiv-view.c | 69 +++++++++++++++++++++++++++++++++++++++++++++++--------------- 1 file changed, 53 insertions(+), 16 deletions(-) diff --git a/fiv-view.c b/fiv-view.c index 1fa4880..b16dee1 100644 --- a/fiv-view.c +++ b/fiv-view.c @@ -543,9 +543,9 @@ fiv_view_draw(GtkWidget *widget, cairo_t *cr) double x = 0; double y = 0; if (self->hadjustment) - x = -gtk_adjustment_get_value(self->hadjustment); + x = -floor(gtk_adjustment_get_value(self->hadjustment)); if (self->vadjustment) - y = -gtk_adjustment_get_value(self->vadjustment); + y = -floor(gtk_adjustment_get_value(self->vadjustment)); if (w < allocation.width) x = round((allocation.width - w) / 2.); if (h < allocation.height) @@ -645,15 +645,52 @@ set_scale_to_fit(FivView *self, bool scale_to_fit) } static gboolean -set_scale(FivView *self, double scale) +set_scale(FivView *self, double scale, const GdkEvent *event) { - if (self->scale != scale) { - self->scale = scale; - g_object_notify_by_pspec(G_OBJECT(self), view_properties[PROP_SCALE]); - prescale_page(self); + if (self->scale == scale) + goto out; - 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); } @@ -663,7 +700,7 @@ set_scale_to_fit_width(FivView *self) double w = get_surface_dimensions(self).width; int allocated = gtk_widget_get_allocated_width(GTK_WIDGET(self)); if (ceil(w * self->scale) > allocated) - set_scale(self, allocated / w); + set_scale(self, allocated / w, NULL); } static void @@ -672,7 +709,7 @@ set_scale_to_fit_height(FivView *self) double h = get_surface_dimensions(self).height; int allocated = gtk_widget_get_allocated_height(GTK_WIDGET(self)); if (ceil(h * self->scale) > allocated) - set_scale(self, allocated / h); + set_scale(self, allocated / h, NULL); } static gboolean @@ -686,9 +723,9 @@ fiv_view_scroll_event(GtkWidget *widget, GdkEventScroll *event) switch (event->direction) { 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: - return set_scale(self, self->scale / SCALE_STEP); + return set_scale(self, self->scale / SCALE_STEP, (GdkEvent *) event); default: // For some reason, native GdkWindows may also get GDK_SCROLL_SMOOTH. // 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 && !(event->state & gtk_accelerator_get_default_mod_mask()) && 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) ->key_press_event(widget, event); @@ -1538,11 +1575,11 @@ fiv_view_command(FivView *self, FivViewCommand command) info(self); 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: - set_scale(self, self->scale / SCALE_STEP); + set_scale(self, self->scale / SCALE_STEP, NULL); 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: set_scale_to_fit_width(self); break; case FIV_VIEW_COMMAND_FIT_HEIGHT: -- cgit v1.2.3