Question

I m 绘制地图编辑网络应用程序,使我们能够建立和编辑多线、多角等。我在网上找不到一些关于无所作为的信息,我发现有人对“我们的需要不成事实”和“在我指挥模式使用关闭的情况下”,但我想到的是,这同一个完全的无所事事的/充满活力的界面之间有相当的路。

因此,我的问题是我的问题(我相信,我的好人选):

Should I manage the stack, or is there a way to send my commands to the browser s stack ? (and how do I handle native commands, like text edits in textifields in this case)
how do I handle "command compression" (command grouping) when some commands are browser native
How do I detect the undo (ctrl+z) keystroke?
If I register a keyup event, how do I decide if I prevent default or not?
If not, can I register some undoevent handler somewhere ?
Users are not used to undo on the web, how can I "train" them to explore/undo on my application ?

Answer 1

您需要具备制造和删除物体的职能。然后将这些职能转嫁给单人经理。 See the demo file of my javascript undo Manager: https://github.com/ArthurClemens/Javascript-Undo-Manager

《血清法》显示了血管,但该法典是空洞的。

它含有关键的约束力,但可以帮助您采取初步步骤。

我我已在与纽埃和雷多州一起在网络应用中利用了这一信息,随后可以节省费用。

Answer 2

这里是使用Knockout JS的N-level undo样本:

(function() {
    
    //current state would probably come from the server, hard coded here for example
    var currentState = JSON.stringify({
        firstName:  Paul ,
        lastName:  Tyng ,
        text:  Text  
    })
       , undoStack = [] //this represents all the previous states of the data in JSON format
        , performingUndo = false //flag indicating in the middle of an undo, to skip pushing to undoStack when resetting properties
        , viewModel = ko.mapping.fromJSON(currentState); //enriching of state with observables
        
    
    //this creates a dependent observable subscribed to all observables 
    //in the view (toJS is just a shorthand to traverse all the properties)
    //the dependent observable is then subscribed to for pushing state history
    ko.dependentObservable(function() {
        ko.toJS(viewModel); //subscribe to all properties    
    }, viewModel).subscribe(function() {
        if(!performingUndo) {
        undoStack.push(currentState);
        currentState = ko.mapping.toJSON(viewModel);
    }
    });
        
    //pops state history from undoStack, if its the first entry, just retrieve it
        window.undo = function() {
            performingUndo = true;
            if(undoStack.length > 1)
            {
                currentState = undoStack.pop();
                ko.mapping.fromJSON(currentState, {}, viewModel);
            }
            else {
                currentState = undoStack[0];
                ko.mapping.fromJSON(undoStack[0], {}, viewModel);
            }
            performingUndo = false;
    };
    
    ko.applyBindings(viewModel);
})();

<script src="https://cdnjs.cloudflare.com/ajax/libs/knockout/1.2.1/knockout-min.js"></script>
<script src="https://cdnjs.cloudflare.com/ajax/libs/jquery/1.6.3/jquery.min.js"></script>
<div>
    <button data-bind="click: function() { undo(); }">Undo</button>
    <input data-bind="value: firstName" />
    <input data-bind="value: lastName" />
    <textarea data-bind="value: text"></textarea>
</div>

它使用MVVER模型,因此,贵国的页数以它保存历史的 j印标语表示。

Answer 3

Cappuccino自动支持工作的方式是向单人管理人说明哪些财产应当无法使用。例如,在你管理学生记录时,你可以做以下事情:

[theUndoManager observeChangesForKeyPath:@"firstName" ofObject:theStudent];
[theUndoManager observeChangesForKeyPath:@"lastName" ofObject:theStudent];

现在,无论学生名称如何在教育、青年和体育部中发生变化,打上 un子将自动恢复。简明扼要还自动处理同一跑道的合并变化,将文件标记为“dirty”(“need Save”),而有些项目属于“unty”,等等(换言之,上述内容应当是为了支持undo。

另一个例子是,如果你想要增加和删除学生,那么你就是:

[theUndoManager observeChangesForKeyPath:@"students" ofObject:theClass];

由于“学生”是各环礁岛的一系列学生,因此将跟踪这些阵列的增减情况。

友情链接