ported rewrite2 to c3

src/ugui_layout.c3

@@ -0,0 +1,153 @@
+module ugui;
+
+
+fn void! Ctx.layout_set_row(&ctx)
+{
+	Id parent_id = ctx.tree.get(ctx.active_div)!;
+	Elem *parent = ctx.cache.search(parent_id)!;
+
+	if (parent.type != ETYPE_DIV) {
+		// what?
+		return UgError.UNEXPECTED_ELEMENT?;
+	}
+
+	parent.div.layout = LAYOUT_ROW;
+}
+
+fn void! Ctx.layout_set_column(&ctx)
+{
+	Id parent_id = ctx.tree.get(ctx.active_div)!;
+	Elem *parent = ctx.cache.search(parent_id)!;
+
+	if (parent.type != ETYPE_DIV) {
+		// what?
+		return UgError.UNEXPECTED_ELEMENT?;
+	}
+
+	parent.div.layout = LAYOUT_COLUMN;
+}
+
+fn void! Ctx.layout_set_floating(&ctx)
+{
+	Id parent_id = ctx.tree.get(ctx.active_div)!;
+	Elem *parent = ctx.cache.search(parent_id)!;
+
+	if (parent.type != ETYPE_DIV) {
+		// what?
+		return UgError.UNEXPECTED_ELEMENT?;
+	}
+
+	parent.div.layout = LAYOUT_FLOATING;
+}
+
+fn void! Ctx.layout_next_row(&ctx)
+{
+	Id parent_id = ctx.tree.get(ctx.active_div)!;
+	Elem *parent = ctx.cache.search(parent_id)!;
+
+	if (parent.type != ETYPE_DIV) {
+		// what?
+		return UgError.UNEXPECTED_ELEMENT?;
+	}
+
+	parent.div.origin_r = Point{
+	    .x = parent.rect.x,
+	    .y = parent.div.origin_c.y,
+	};
+	parent.div.origin_c = parent.div.origin_r;
+}
+
+fn void! Ctx.layout_next_column(&ctx)
+{
+	Id parent_id = ctx.tree.get(ctx.active_div)!;
+	Elem *parent = ctx.cache.search(parent_id)!;
+
+	if (parent.type != ETYPE_DIV) {
+		// what?
+		return UgError.UNEXPECTED_ELEMENT?;
+	}
+
+	parent.div.origin_c = Point{
+	    .x = parent.div.origin_r.x,
+	    .y = parent.rect.y,
+	};
+	parent.div.origin_r = parent.div.origin_c;
+}
+
+// position the rectangle inside the parent according to the layout
+fn Rect Ctx.position_element(&ctx, Elem *parent, Rect rect, bool style = false)
+{
+	Rect  elem_rect;
+	Point origin;
+
+	// 1. Select the right origin
+	switch (parent.div.layout) {
+	case LAYOUT_ROW:
+		origin = parent.div.origin_r;
+	case LAYOUT_COLUMN:
+		origin = parent.div.origin_c;
+	case LAYOUT_FLOATING: // none
+	default:
+		// Error
+	}
+
+	// 2. Position the rect
+	elem_rect.x = origin.x + rect.x;
+	elem_rect.y = origin.y + rect.y;
+
+	// 3. Calculate width & height
+	// TODO: what about negative values?
+	// FIXME: account for origin offset!!
+	elem_rect.w = rect.w > 0 ? rect.w : parent.rect.w;
+	elem_rect.h = rect.h > 0 ? rect.h : parent.rect.h;
+
+	// 4. Update the origins of the parent
+	parent.div.origin_r = Point{
+	    .x = elem_rect.x + elem_rect.w,
+	    .y = elem_rect.y,
+	};
+	parent.div.origin_c = Point{
+	    .x = elem_rect.x,
+	    .y = elem_rect.y + elem_rect.h,
+	};
+
+	// if using the style then apply margins
+	// FIXME: this does not work
+	if (style && parent.div.layout != LAYOUT_FLOATING) {
+		elem_rect.x += ctx.style.margin.x;
+		elem_rect.y += ctx.style.margin.y;
+
+		// total keep-out borders
+		Rect margin_tot = {
+		    .x = ctx.style.padding.x + ctx.style.border.x +
+		         ctx.style.margin.x,
+		    .y = ctx.style.padding.y + ctx.style.border.y +
+		         ctx.style.margin.y,
+		    .w = ctx.style.padding.w + ctx.style.border.x +
+		         ctx.style.margin.w,
+		    .h = ctx.style.padding.h + ctx.style.border.x +
+		         ctx.style.margin.h,
+		};
+
+		parent.div.origin_r.x += margin_tot.x + margin_tot.w;
+		// parent.div.origin_r.y += margin_tot.h;
+
+		// parent.div.origin_c.x += margin_tot.w;
+		parent.div.origin_c.y += margin_tot.y + margin_tot.h;
+	}
+
+	/*
+	        printf(
+	            "positioning rect: %lx {%d %d %d %d}(%d %d %d %d) . {%d %d %d
+	   %d}\n", parent.id, rect.x, rect.y, rect.w, rect.h, parent.rect.x,
+	            parent.rect.y,
+	            parent.rect.w,
+	            parent.rect.h,
+	            elem_rect.x,
+	            elem_rect.y,
+	            elem_rect.w,
+	            elem_rect.h
+	        );
+	*/
+	return elem_rect;
+}