300: Always show undo button.

Help muscle memory by always showing the undo button in the same place.

3 files changed, 23 insertions, 2 deletions

diff --git a/play.html b/play.html
index fe3cb5e..8180fd1 100644
--- a/play.html
+++ b/play.html
@@ -293,8 +293,8 @@
 		<button id="button_draw" onclick="on_draw()" class="hide">Draw</button>
 		<button id="button_battle" onclick="on_battle()" class="hide">Battle</button>
 		<button id="button_pass" onclick="on_pass()" class="hide">Pass</button>
-		<button id="button_undo" onclick="on_undo()" class="hide">Undo</button>
 		<button id="button_next" onclick="on_next()" class="hide">Next</button>
+		<button id="button_undo" onclick="on_undo()" class="hide">Undo</button>
 
 		<div id="rematch_button" class="image_button hide" onclick="send_rematch()"><img src="/images/cycle.svg"></div>
 		<div id="exit_button" class="image_button hide" onclick="send_exit()"><img src="/images/exit-door.svg"></div>
diff --git a/rules.js b/rules.js
index e1218e1..c209f00 100644
--- a/rules.js
+++ b/rules.js
@@ -9,6 +9,7 @@
 // Diary: 2021-05-03 - Monday Night - Clean up reaction event game states.
 // Diary: 2021-05-04 - Tuesday Night - Event code cleanup.
 // Diary: 2021-05-08 - Saturday Afternoon - Polish game log messages.
+// Diary: 2021-10-01 - Friday Afternoon - Fix bugs.
 
 // Acropolis on Fire -- if sudden death of the great king, does greece get 6 or 5 talents for the next campaign?
 // leonidas + miltiades -- forbid combination?
diff --git a/ui.js b/ui.js
index 5c95765..d37adf6 100644
--- a/ui.js
+++ b/ui.js
@@ -267,6 +267,26 @@ function show_marker(id, class_name, show = 1, enabled = 0) {
 	elt.className = class_name;
 }
 
+function show_undo_button(sel, action, use_label = false) {
+	let button = document.querySelector(sel);
+	if (game.actions) {
+		button.classList.remove("hide");
+		if (game.actions && action in game.actions) {
+			if (game.actions[action]) {
+				if (use_label)
+					button.textContent = game.actions[action];
+				button.disabled = false;
+			} else {
+				button.disabled = true;
+			}
+		} else {
+			button.disabled = true;
+		}
+	} else {
+		button.classList.add("hide");
+	}
+}
+
 function on_update() {
 	document.getElementById("greek_info").textContent = greek_info();
 	document.getElementById("persian_info").textContent = persian_info();
@@ -285,7 +305,7 @@ function on_update() {
 	show_action_button("#button_draw", "draw");
 	show_action_button("#button_next", "next");
 	show_action_button("#button_pass", "pass");
-	show_action_button("#button_undo", "undo");
+	show_undo_button("#button_undo", "undo");
 
 	if (game.actions && game.actions.destroy)
 		document.getElementById("bridge").className = "show destroy";