src/redakcja/static/js/wiki/undo.js

   1 {
   2
   3     class Undo {
   4         maxItems = 100;
   5         stack = [];
   6         position = 0;
   7
   8         stats = {size: 0};
   9
  10         constructor() {
  11             $(() => {
  12                 this.$undo = $("#undoBtn");
  13                 this.$undo.on('click', () => {CurrentDocument.undo();})
  14                 this.$redo = $("#redoBtn");
  15                 this.$redo.on('click', () => {CurrentDocument.redo();})
  16                 this.$stats = $("#undoStats");
  17             })
  18         }
  19
  20         refresh() {
  21             this.$undo.prop('disabled', !this.canUndo);
  22             this.$redo.prop('disabled', !this.canRedo);
  23             this.$undo.attr('title', 'undo\n\n' + this.renderStats())
  24         }
  25
  26         renderStats() {
  27             return this.stats.size / 1e6;
  28         }
  29
  30         push(state) {
  31             // Has the state actually changed?
  32             if (state == this.materialize(this.position))
  33                 return;
  34
  35             while (this.position) {
  36                 this.pop();
  37                 --this.position;
  38             }
  39
  40             this.put(state);
  41             this.trim();
  42             this.refresh();
  43         }
  44         pop() {
  45             this.stats.size -= this.stack[0].length;
  46             return this.stack.shift()
  47         }
  48         put(state) {
  49             this.stack.unshift(state);
  50             this.stats.size += state.length;
  51         }
  52         trim() {
  53             while (this.stack.length > this.maxItems) {
  54                 this.stats.size -= this.stack.pop().length;
  55             }
  56         }
  57         materialize(n) {
  58             return this.stack[n];
  59         }
  60
  61         undo() {
  62             if (!this.canUndo) return;
  63             let val = this.materialize(++this.position);
  64             this.refresh();
  65             return val;
  66         }
  67
  68         redo() {
  69             if (!this.canRedo) return;
  70             let val = this.materialize(--this.position);
  71             this.refresh();
  72             return val;
  73         }
  74
  75         get canUndo() {
  76             return this.stack.length > this.position + 1;
  77         }
  78
  79         get canRedo() {
  80             return this.position > 0;
  81         }
  82     }
  83
  84
  85     class TextUndo extends Undo {
  86         stats = {
  87             Items: 0,
  88             Size: 0,
  89             textSize: 0,
  90             textItems: 0,
  91             diffSize: 0,
  92             diffItems: 0,
  93             diffChanges: 0,
  94         }
  95
  96         statsFor(item) {
  97             if (Array.isArray(item)) {
  98                 return {
  99                     diffItems: 1,
 100                     diffChanges: item.length,
 101                     diffSize: JSON.stringify(item).length
 102                 }
 103             } else {
 104                 return {
 105                     textItems: 1,
 106                     textSize: item.length
 107                 }
 108             }
 109         }
 110         addStats(stats) {
 111             for (let i in stats) {
 112                 this.stats[i] += stats[i]
 113             }
 114         }
 115         subStats(stats) {
 116             for (let i in stats) {
 117                 this.stats[i] -= stats[i]
 118             }
 119         }
 120         renderStats() {
 121             this.stats['Items'] = this.stats['textItems'] + this.stats['diffItems'];
 122             this.stats['Size'] = this.stats['textSize'] + this.stats['diffSize'];
 123             let stats = '', v;
 124             for (let k in this.stats) {
 125                 v = this.stats[k];
 126                 if (k.endsWith('Size')) {
 127                     let level = 0;
 128                     while (v > 1000) {
 129                         v /= 1000;
 130                         level++;
 131                     }
 132                     v = Math.round(v)
 133                     v += ['B', 'kB', 'MB', 'GB'][level];
 134                 }
 135                 stats += k + ': ' + v + '\n';
 136             }
 137             return stats;
 138         }
 139
 140
 141         put(state) {
 142             if (this.stack.length) {
 143                 let tip = this.materialize(0);
 144                 this.subStats(this.statsFor(this.stack[0]))
 145                 this.stack[0] = $.wiki.diff(state, tip);
 146                 this.addStats(this.statsFor(this.stack[0]))
 147             }
 148             this.stack.unshift(state);
 149             this.addStats(this.statsFor(state));
 150         }
 151         pop() {
 152             if (this.stack.length > 1) {
 153                 this.subStats(this.statsFor(this.stack[1]))
 154                 this.stack[1] = this.materialize(1);
 155                 this.addStats(this.statsFor(this.stack[1]))
 156             }
 157             this.subStats(this.statsFor(this.stack[0]))
 158             return this.stack.shift();
 159         }
 160         trim() {
 161             while (this.stack.length > this.maxItems) {
 162                 this.subStats(this.statsFor(
 163                     this.stack.pop()
 164                 ));
 165             }
 166         }
 167
 168         materialize(n) {
 169             if (n >= this.stack.length) return;
 170             let state, base_i, i;
 171             for (i = 0; i <= n; ++i) {
 172                 if (!Array.isArray(this.stack[i])) {
 173                     base_i = i;
 174                 }
 175             }
 176             state = this.stack[base_i];
 177             for (i = base_i + 1; i <= n; ++i) {
 178                 state = $.wiki.patch(state, this.stack[i]);
 179             }
 180             return state;
 181         }
 182     }
 183
 184     $.wiki.undo = new TextUndo();
 185 }