From e9b4d14df7a175c8451563d9b383568190304494 Mon Sep 17 00:00:00 2001
From: Aki <please@ignore.pl>
Date: Thu, 9 Sep 2021 21:54:16 +0200
Subject: Prepared handler and main to separate layouting from drawing

---
 text.c | 39 ++++++++++++++++++++++++++-------------
 1 file changed, 26 insertions(+), 13 deletions(-)

diff --git a/text.c b/text.c
index 8ad0d75..c0bd004 100644
--- a/text.c
+++ b/text.c
@@ -44,10 +44,17 @@ struct State
 	cairo_surface_t * surface;
 };
 
+enum Actions
+{
+	ACTION_REDRAW = 1 << 0,
+	ACTION_RELAYOUT = 1 << 1,
+	ACTION_CLOSE = 1 << 2,
+};
+
 int setup(struct State *);
 void finalize(struct State *);
 int handle(struct State *, xcb_generic_event_t *);
-void draw_body(struct State *, union Command *);
+void draw(struct State *, union Command *);
 xcb_visualtype_t * find_visual(xcb_screen_t *);
 
 static const int MARGIN = 20;
@@ -78,9 +85,13 @@ int main(int argc, const char ** argv)
 	}
 	for (;;)
 	{
-		xcb_generic_event_t * e = xcb_wait_for_event(state.c);  // TODO: Change it to poll-like behaviour.
-		if (handle(&state, e))
+		xcb_generic_event_t * e = xcb_wait_for_event(state.c);  // TODO: All events first, then flagged actions.
+		int actions = handle(&state, e);  // Obviously, right now this may have at most one action.
+		if (ACTION_CLOSE & actions)
 			break;
+		// if (ACTION_RELAYOUT & actions)  TODO: Implement separate layouting.
+		if (ACTION_REDRAW & actions)
+			draw(&state, body);
 	}
 	finalize(&state);
 }
@@ -122,20 +133,18 @@ void finalize(struct State * state)
 
 int handle(struct State * state, xcb_generic_event_t * e)
 {
+	int actions = 0;
 	switch (XCB_EVENT_RESPONSE_TYPE(e))
 	{
 	case XCB_KEY_PRESS:
-		free(e);
-		return 1;
+		actions = ACTION_CLOSE;
+		break;
 	case XCB_EXPOSE:
-		cairo_set_source_rgb(state->ctx, 1., 1., 1.);
-		cairo_paint(state->ctx);
-		draw_body(state, body);  // TODO: Redraw outside of handler and don't use global body.
-		cairo_surface_flush(state->surface);
-		xcb_flush(state->c);
+		actions |= ACTION_REDRAW;
 		break;
 	case XCB_CONFIGURE_NOTIFY:
 		;
+		actions |= ACTION_RELAYOUT;
 		xcb_configure_notify_event_t * conf = (xcb_configure_notify_event_t *) e;
 		if (state->width != conf->width || state->height != conf->height)
 		{
@@ -148,7 +157,7 @@ int handle(struct State * state, xcb_generic_event_t * e)
 		break;
 	}
 	free(e);
-	return 0;
+	return actions;
 }
 
 
@@ -166,12 +175,14 @@ xcb_visualtype_t * find_visual(xcb_screen_t * screen)
 }
 
 
-void draw_body(struct State * state, union Command * body)
+void draw(struct State * state, union Command * body)
 {
+	cairo_set_source_rgb(state->ctx, 1., 1., 1.);
+	cairo_paint(state->ctx);
 	PangoFontDescription * desc = pango_font_description_from_string(FONT);
 	cairo_set_source_rgb(state->ctx, 0., 0., 0.);
 	int y = MARGIN;
-	PangoAttrList * attrs = pango_attr_list_new();  // TODO-maybe: Don't recreate attributes lists each redraw?
+	PangoAttrList * attrs = pango_attr_list_new();  // TODO: Store layouts and only relayout if needed.
 	for (union Command * command = body; COMMAND_DONE != command->type; ++command)
 	{
 		switch (command->type)
@@ -206,4 +217,6 @@ void draw_body(struct State * state, union Command * body)
 	}
 	pango_attr_list_unref(attrs);
 	pango_font_description_free(desc);
+	cairo_surface_flush(state->surface);
+	xcb_flush(state->c);
 }
-- 
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