1 files changed, 64 insertions, 12 deletions

diff --git a/js/undo.js b/js/undo.js
index 3bdc0a9..cc7f2a5 100644
--- a/js/undo.js
+++ b/js/undo.js
@@ -78,16 +78,44 @@ var save_focused_lex = function(state){
   save_lex(x, y, canvas.aa[y][x], state)
 }
 var save_rect = function(xpos, ypos, w, h, state){
+  if (w === 0 || h === 0) return;
   state = state || current_undo;
+  state.rects = state.rects || []
   var aa = canvas.aa;
   
+  var rect = {x: xpos, y: ypos, w: w, h: h, lexs: []}
+  var lexs = rect.lexs
+
   var xlen = xpos + w
   var ylen = ypos + h
 
-  for (var x = xpos; x < xlen; x++){
-    for (var y = ypos; y < ylen; y++){
-      save_lex(x, y, aa[y][x], state)
+  for (var y = ypos; y < ylen; y++){
+    var aay = aa[y]
+    for (var x = xpos; x < xlen; x++){
+      lexs.push(new LexState(aay[x]))
+    }
+  }
+  state.rects.push(rect)
+}
+var save_resize = function(w, h, old_w, old_h, state){
+  state = state || current_undo
+  save_size(old_w, old_h, state)
+  if (old_w > w){
+    // .----.
+    // |   XX
+    // |___XX
+    save_rect(w, 0, old_w - w, old_h, state)
+    if (old_h > h){
+      // .----.
+      // |    |
+      // |XXX_|
+      save_rect(0, h, w, old_h - h, state)
     }
+  } else if (old_h > h){
+    // .----.
+    // |    |
+    // |XXXX|
+    save_rect(0, h, old_w, old_h - h, state)
   }
 }
 
@@ -97,26 +125,46 @@ var restore_state = function(state){
   // if it doesn't have one, generate one
   var make_redo = ! ('redo' in state || 'undo' in state);
   var aa = canvas.aa
-  var lexs = state.lexs
+  var lex, lexs; // = state.lexs
 
   if (make_redo){
     state.redo = new_redo()
   }
 
+  // copy saved rects that intersect with current canvas size
+  // important to do this before resizing canvas
+  if (make_redo && 'rects' in state){
+    for (var ri=0, rect; rect=state.rects[ri]; ri++){
+      if (rect.x >= canvas.w ||
+          rect.y >= canvas.h) continue;
+      var w = Math.min(rect.w, canvas.w - rect.x)
+      var h = Math.min(rect.h, canvas.h - rect.y)
+      save_rect(rect.x, rect.y, w, h, state.redo)
+    }
+  }
+
   if ('size' in state){
     if (make_redo){
-      save_size(canvas.w, canvas.h, state.redo)
-      // note that resizing canvas redo saves the whole canvas instead of
-      // just the changed part which is inefficient...
-      save_rect(0,0, canvas.w, canvas.h, state.redo)
-      make_redo = false // already saved whole canvas, skip lexs below
+      save_resize(state.size.w, state.size.h, canvas.w, canvas.h, state.redo)
+    }
+    canvas.resize(state.size.w, state.size.h, true);
+  }
+
+  if ('rects' in state){
+    for (var ri=0, rect; rect=state.rects[ri]; ri++){
+      lexs = rect.lexs
+      for (var li=0; lex=lexs[li]; li++){
+        var x = (li % rect.w) + rect.x
+        var y = ((li / rect.w)|0) + rect.y
+        aa[y][x].assign(lex)
+      }
     }
-    canvas.resize(state.size.w, state.size.h);
   }
 
+  lexs = state.lexs
   for (var key in lexs){
     var xy = key.split(',');
-    var lex = aa[xy[1]][xy[0]]
+    lex = aa[xy[1]][xy[0]]
     if (make_redo)
       save_lex(xy[0], xy[1], lex, state.redo)
     lex.assign(lexs[key])
@@ -125,7 +173,10 @@ var restore_state = function(state){
   if ('focus' in state){
     canvas.focus_x = state.focus.x
     canvas.focus_y = state.focus.y
-    if (focused_input === canvas) canvas.focus()
+    if (current_canvas === canvas){ // &&)
+      canvas.focus()
+    }
+    // if (focused_input === canvas) canvas.focus()
   }
 }
 
@@ -166,6 +217,7 @@ return {
   save_lex: save_lex,
   save_focused_lex: save_focused_lex,
   save_rect: save_rect,
+  save_resize: save_resize,
   undo: undo,
   redo: redo
 }