使用 konva 在画布中绘制类似网格的电子表格

Posted 2023-03-25

【中文标题】使用 konva 在画布中绘制类似网格的电子表格

【英文标题】：Drawing a spreadsheet like grid in canvas with konva

【发布时间】：2019-06-26 20:55:18

【问题描述】：

我正在使用 html5 画布和 Konvajs 画布库进行类似甘特图的任务显示。

将甘特图解构为它的组件使我目前看到如下视图。这里1是任务列表，2是任务栏区域，3是任务栏，4是文本单元格。

对于这个问题，我正在寻找构建 1 和 4 的代码。要显示的数据将在带有嵌套任务列表的普通 JS 对象中传递，其中每个任务都有一个编号、名称、分配给的人名、开始日期、结束日期、持续时间和完成百分比。

因此，要求是能够构建类似电子表格的面板，如甘特图左侧所示。

我已经开发了一些部分，我将发布作为答案。然而，这似乎是一种常见的需求，我希望有人可以将代码剪切并粘贴到 SO 中以引领潮流。

注意：示例图像中的甘特图来自Vertex42。

【参考方案1】：

所以这是我自己在一种方法上的笨拙尝试。任何人都可以改进它还是我走错了路。

编辑：我现在有一个新兴的组件，用于将文本绘制到类似电子表格的单元格中，包括完成百分比着色。为了保持这个答案整洁，这个附加组件位于this codepen。

// this is the object that defines our grid
// 
var gridData =  name: 'grid1', width: 350, height: 400, rowHeight: 24, padding: 4, fill: 'azure', gridLineColor: '#ccc',  header: size: 16, fill: 'black', color: 'white' ,  data: size: 16, fill: 'azure', color: 'black' ,  
  row: [
       cells:   // row 1
        [
           width: 50, text: 'Item', style: 'header',
           width: 240, text: 'Name', style: 'header',
           width: 60, text: 'Status', style: 'header',
        ]
      ,
       cells:    // row 2
        [
           text: '1',
           text: 'Find tea pot',
           text: '100%',
        ]
      ,
       cells:    // row 3
        [
           text: '2',
           text: 'Boil water',
           text: '60%',
        ]
      
  ]


// From here on could be wrapped into a component that churns out grids. Maybe you pass in the id of the stage container
// and the data model you want to produce, etc.

// Set up the canvas / stage
var stage = new Konva.Stage(container: 'container1', width: 600, height: 300);

// Add a layer 
var layer = new Konva.Layer(draggable: false);
stage.add(layer);

// make a main group for the grid, call it a panel. Assigning a name may be handy later
var panel = new Konva.Group(name: gridData.name);  
layer.add(panel);  // Add the panel to the layer

// a group has no visual properties. Add a background rect to hold the colour fill
var panelRect = new Konva.Rect(width: gridData.width, height: gridData.height, fill: gridData.fill) 
panel.add(panelRect);

var topLeft = x: 0, y: 0; // Since we are drawing a grid, we need to compute the position of each cell
for (var i = 0; i < gridData.row.length; i = i + 1)

  topLeft.x = 0; // reset x at start of each row
  
  // iterate for each cell on the row
  for (var j = 0; j < gridData.row[i].cells.length; j = j + 1)

    var cell = new Konva.Rect(name: 'cellBg',                          // assign a name for later searching 
                               x: topLeft.x, y: topLeft.y,              // position as computed 
                               width:  gridData.row[0].cells[j].width,  // use the first row from celldate to get the cell width
                               height: gridData.rowHeight,              // grid has a uniform row height
                               stroke: gridData.gridLineColor,          // and line colour
                               strokeWidth: 1,                          // use a set line width but you can add to the gridData object as needed.
                               fill: (i === 0 ? gridData.header.fill : gridData.data.fill),              // use the given header text color
                              );
    panel.add(cell);

    // Add text to the cell. Note that if you wanted to be using alignments you would need to draw the text off-screen and 
    // get width/height of that text then use those values for positioning calculations. Once you have the rect size of the
    // text, all the alignments are simple math.
    var text = new Konva.Text( x: topLeft.x + gridData.padding,        // add padding to locate the text nicely into the cell 
                               y: topLeft.y + gridData.padding, 
                                                                        // use the given text size
                               fontSize: (i === 0 ? gridData.header.size : gridData.data.size),
                                                                       // use the given header text color
                               fill: (i === 0 ? gridData.header.color : gridData.data.color),              
                               text: gridData.row[i].cells[j].text,   // set the text value.
                               listening: false                       // stop text interfering with mouse events
                              );
    panel.add(text);
    
    cell.on('mouseover', function(evt)
      var shape = evt.target;
      $(shape).data('bgColor', shape.fill());
      shape.fill('lime');
      layer.draw();      
    )
    cell.on('mouseout', function(evt)
      var shape = evt.target;
      shape.fill($(shape).data('bgColor'));
      layer.draw();      
    )

    
    topLeft.x = topLeft.x + gridData.row[0].cells[j].width;             // offset the computed next cell x value by the width of the cell  
  
  
  topLeft.y = topLeft.y +  gridData.rowHeight;                          // offset the computed next cell y value by the height of the row   


layer.draw();
stage.draw();

<script src="https://ajax.googleapis.com/ajax/libs/jquery/2.1.1/jquery.min.js"></script>
<script src="https://cdnjs.cloudflare.com/ajax/libs/konva/2.5.1/konva.min.js"></script>
<div id='container1' style="width: 300px, height: 200px; background-color: silver;"></div>