p5.js Element addClass()用法及代码示例

function setup() { 
  createCanvas(550, 300); 
  textSize(18); 
  
  text("Click on the buttons to add the given " + 
       "class to the element", 20, 20); 
  
  setBtn =  
    createButton("Add given class to element"); 
  setBtn.position(30, 40); 
  setBtn.mouseClicked(addNewClass); 
  
  setBtn =  
    createButton("Show current classes"); 
  setBtn.position(300, 40); 
  setBtn.mouseClicked(showClasses); 
  
  class_name = createInput('class1'); 
  class_name.position(30, 80); 
  
  // Create a new p5.Element 
  tmpElement = createElement("div"); 
} 
  
function addNewClass() { 
  clear(); 
  
  // Get the class to set 
  let classToSet = class_name.value(); 
  
  // Set the class of the element 
  tmpElement.addClass(classToSet); 
  
  text("Class added with name:" +  
       classToSet, 30, 120); 
  
  text("Click on the button to add the given " + 
       "class to the element", 20, 20); 
} 
  
function showClasses() { 
  clear(); 
  
  // Get the classes of the element 
  let setClasses = tmpElement.class(); 
  
  // Display the clases 
  text("The classes of the element are:" + 
       setClasses, 30, 120); 
  
  text("Click on the button to add the given " + 
       "class to the element", 20, 20); 
}