From 7ce03bac9d4b84842f029c8b83df120975e6164e Mon Sep 17 00:00:00 2001 From: Přemysl Janouch Date: Sat, 8 Jan 2011 12:05:59 +0100 Subject: Make LdCanvas zoom on mouse wheel. --- src/ld-canvas.c | 47 ++++++++++++++++++++++++++++++++++++++++++----- 1 file changed, 42 insertions(+), 5 deletions(-) diff --git a/src/ld-canvas.c b/src/ld-canvas.c index aa6a1b3..8d04b59 100644 --- a/src/ld-canvas.c +++ b/src/ld-canvas.c @@ -160,6 +160,7 @@ static void on_adjustment_value_changed (GtkAdjustment *adjustment, LdCanvas *self); static void on_size_allocate (GtkWidget *widget, GtkAllocation *allocation, gpointer user_data); +static void update_adjustments (LdCanvas *self); static void diagram_connect_signals (LdCanvas *self); static void diagram_disconnect_signals (LdCanvas *self); @@ -175,6 +176,8 @@ static gboolean on_button_press (GtkWidget *widget, GdkEventButton *event, gpointer user_data); static gboolean on_button_release (GtkWidget *widget, GdkEventButton *event, gpointer user_data); +static gboolean on_scroll (GtkWidget *widget, GdkEventScroll *event, + gpointer user_data); static void ld_canvas_color_set (LdCanvasColor *color, gdouble r, gdouble g, gdouble b, gdouble a); @@ -310,6 +313,8 @@ ld_canvas_init (LdCanvas *self) G_CALLBACK (on_button_press), NULL); g_signal_connect (self, "button-release-event", G_CALLBACK (on_button_release), NULL); + g_signal_connect (self, "scroll-event", + G_CALLBACK (on_scroll), NULL); g_object_set (self, "can-focus", TRUE, NULL); @@ -474,10 +479,8 @@ on_size_allocate (GtkWidget *widget, GtkAllocation *allocation, gpointer user_data) { LdCanvas *self; - gdouble scale; self = LD_CANVAS (widget); - scale = ld_canvas_get_scale_in_px (self); /* FIXME: If the new allocation is bigger, we may see more than * what we're supposed to be able to see -> adjust X and Y. @@ -485,17 +488,28 @@ on_size_allocate (GtkWidget *widget, GtkAllocation *allocation, * If the visible area is just so large that we must see more, * let's disable the scrollbars in question. */ + update_adjustments (self); +} + +static void +update_adjustments (LdCanvas *self) +{ + gdouble scale; + + scale = ld_canvas_get_scale_in_px (self); + if (self->priv->adjustment_h) { - self->priv->adjustment_h->page_size = allocation->width / scale; + self->priv->adjustment_h->page_size + = GTK_WIDGET (self)->allocation.width / scale; self->priv->adjustment_h->value = self->priv->x - self->priv->adjustment_h->page_size / 2; gtk_adjustment_changed (self->priv->adjustment_h); } - if (self->priv->adjustment_v) { - self->priv->adjustment_v->page_size = allocation->height / scale; + self->priv->adjustment_v->page_size + = GTK_WIDGET (self)->allocation.height / scale; self->priv->adjustment_v->value = self->priv->y - self->priv->adjustment_v->page_size / 2; gtk_adjustment_changed (self->priv->adjustment_v); @@ -1006,6 +1020,29 @@ on_button_release (GtkWidget *widget, GdkEventButton *event, gpointer user_data) return FALSE; } +static gboolean +on_scroll (GtkWidget *widget, GdkEventScroll *event, gpointer user_data) +{ + LdCanvas *self; + + self = LD_CANVAS (widget); + switch (event->direction) + { + case GDK_SCROLL_UP: + self->priv->zoom *= 1.5; + break; + case GDK_SCROLL_DOWN: + self->priv->zoom /= 1.5; + break; + default: + return FALSE; + } + + update_adjustments (self); + gtk_widget_queue_draw (widget); + return TRUE; +} + static gboolean on_expose_event (GtkWidget *widget, GdkEventExpose *event, gpointer user_data) { -- cgit v1.2.3-70-g09d2