eeshow/gui/: difference display can now be switched with New/Old/Diff

Still need a GUI way to do the same.

eeshow/README

@@ -174,4 +174,7 @@ Delete or Backspace	go to the next higher sheet in hierarchy
 PgUp			go to the previous sheet in sequence
 PgDn			go to the next sheet in sequence
 Up or Down		invoke the revision history (WIP)
+D			when comparing revisions, show difference (default)
+N			show newer sheet
+O			show older sheet
 Q			quit the viewer

eeshow/gui/common.h

@@ -94,6 +94,12 @@ struct gui_ctx {
 
 	struct gui_sheet *curr_sheet;
 				/* current sheet, always on new_hist */
+
+	enum {
+		diff_new,	/* show only new sheet */
+		diff_old,	/* show only old sheet */
+		diff_delta,	/* show delta */
+	} diff_mode;
 	struct gui_hist *new_hist;
 	struct gui_hist *old_hist; /* NULL if not comparing */
 

eeshow/gui/gui.c

@@ -378,6 +378,7 @@ int gui(unsigned n_args, char **args, bool recurse, int limit)
 		.pop_origin	= NULL,
 		.glabel		= NULL,
 		.aois		= NULL,
+		.diff_mode	= diff_delta,
 		.old_hist	= NULL,
 		.hist_y_offset 	= 0,
 		.hist_size	= 0,

eeshow/gui/history.c

@@ -130,6 +130,8 @@ static void click_history(void *user)
 		abort();
 	}
 
+	ctx->diff_mode = diff_delta;
+
 	if (ctx->new_hist->age > ctx->old_hist->age) {
 		swap(ctx->new_hist, ctx->old_hist);
 		if (ctx->selecting == sel_old)

eeshow/gui/render.c

@@ -72,15 +72,15 @@ static inline int cy(int y, int yo, float scale)
 }
 
 
-static void highlight_glabel(const struct gui_ctx *ctx, cairo_t *cr,
+static void highlight_glabel(const struct gui_ctx *ctx,
-    int x, int y, float f)
+    const struct gui_sheet *sheet,  cairo_t *cr, int x, int y, float f)
 {
 	const struct sch_obj *obj;
 
 	if (!ctx->glabel)
 		return;
 
-	for (obj = ctx->curr_sheet->sch->objs; obj; obj = obj->next) {
+	for (obj = sheet->sch->objs; obj; obj = obj->next) {
 		const struct dwg_bbox *bbox = &obj->u.text.bbox;
 
 		if (obj->type != sch_obj_glabel)
@@ -127,8 +127,13 @@ static gboolean on_draw_event(GtkWidget *widget, cairo_t *cr,
 	y = -(sheet->ymin + ctx->y) * f + alloc.height / 2;
 
 	cro_canvas_prepare(cr);
-	if (!ctx->old_hist) {
+	if (!ctx->old_hist || ctx->diff_mode == diff_new) {
-		highlight_glabel(ctx, cr, x, y, f);
+		highlight_glabel(ctx, sheet, cr, x, y, f);
+		cro_canvas_draw(sheet->gfx_ctx, cr, x, y, f);
+	} else if (ctx->diff_mode == diff_old) {
+		sheet = find_corresponding_sheet(ctx->old_hist->sheets,
+		    ctx->new_hist->sheets, ctx->curr_sheet);
+		highlight_glabel(ctx, sheet, cr, x, y, f);
 		cro_canvas_draw(sheet->gfx_ctx, cr, x, y, f);
 	} else {
 #if 0

eeshow/gui/sheet.c

@@ -414,6 +414,7 @@ static void sheet_key(void *user, int x, int y, int keyval)
 	case '*':
 		zoom_to_extents(ctx);
 		break;
+
 	case GDK_KEY_Home:
 		if (sheet != ctx->new_hist->sheets)
 			go_to_sheet(ctx, ctx->new_hist->sheets);
@@ -438,6 +439,20 @@ static void sheet_key(void *user, int x, int y, int keyval)
 	case GDK_KEY_KP_Down:
 		show_history(ctx, sel_old);
 		break;
+
+	case GDK_KEY_n:
+		ctx->diff_mode = diff_new;
+		redraw(ctx);
+		break;
+	case GDK_KEY_o:
+		ctx->diff_mode = diff_old;
+		redraw(ctx);
+		break;
+	case GDK_KEY_d:
+		ctx->diff_mode = diff_delta;
+		redraw(ctx);
+		break;
+
 	case GDK_KEY_q:
 		gtk_main_quit();
 	}