Image Uploads

client-data/board.html

@@ -102,6 +102,7 @@
 	<script src="../tools/grid/grid.js"></script>
 	<script src="../tools/download/download.js"></script>
 	<script src="../tools/zoom/zoom.js"></script>
+	<script src="../tools/image/image.js"></script>
 	{{#moderator}}<script src="../tools/clear/clear.js"></script>{{/moderator}}
 	<script src="../js/canvascolor.js"></script>
 </body>

client-data/tools/image/image.js

@@ -0,0 +1,276 @@
+
+/**
+ *                        WHITEBOPHIR
+ *********************************************************
+ * @licstart  The following is the entire license notice for the
+ *  JavaScript code in this page.
+ *
+ * Copyright (C) 2013  Ophir LOJKINE
+ *
+ *
+ * The JavaScript code in this page is free software: you can
+ * redistribute it and/or modify it under the terms of the GNU
+ * General Public License (GNU GPL) as published by the Free Software
+ * Foundation, either version 3 of the License, or (at your option)
+ * any later version.  The code is distributed WITHOUT ANY WARRANTY;
+ * without even the implied warranty of MERCHANTABILITY or FITNESS
+ * FOR A PARTICULAR PURPOSE.  See the GNU GPL for more details.
+ *
+ * As additional permission under GNU GPL version 3 section 7, you
+ * may distribute non-source (e.g., minimized or compacted) forms of
+ * that code without the copy of the GNU GPL normally required by
+ * section 4, provided you include this license notice and a URL
+ * through which recipients can access the Corresponding Source.
+ *
+ * @licend
+ */
+
+(function () { //Code isolation
+  const drawingArea = document.getElementById('board');
+  const canvas = document.getElementById('canvas');
+  const newImageDropPoint = {
+    x: 0,
+    y: 0,
+  };
+
+  const fileInput = document.createElement('input');
+  fileInput.type = 'file';
+  fileInput.accept = 'image/*';
+
+  function onFileInputChange(event) {
+    uploadImage(event.target.files[0], {
+      x: newImageDropPoint.x,
+      y: newImageDropPoint.y,
+    });
+  }
+
+  function promptForImage(x, y, event) {
+    // Get the position of the click on the canvas so when the user uploads
+    // an image, we can draw it at the same position.
+    newImageDropPoint.x = x;
+    newImageDropPoint.y = y;
+    fileInput.click();
+  }
+
+  function draw(data) {
+    Tools.drawingEvent = true;
+    switch (data.type) {
+      case "image":
+        createImageElement(data);
+        break;
+      case "update":
+        var image = svg.getElementById(data['id']);
+        if (!image) {
+          console.error("Image: No image provided!", data['id']);
+        }
+        updateImageElement(image, data);
+        break;
+      default:
+        console.error("Image: Draw instruction with unknown type. ", data);
+        break;
+    }
+  }
+
+  var svg = Tools.svg;
+  /**
+    * Creates a new image element on the canvas, or updates an existing image
+    * with new information.
+    * @param {Object} data - The data to use to create the image.
+    */
+  function createImageElement(data) {
+    var img = svg.getElementById(data.id) || Tools.createSVGElement("image");
+    img.setAttribute("id", data.id);
+    img.setAttribute("href", data.src);
+    img.setAttribute("x", data.x);
+    img.setAttribute("y", data.y);
+
+    updateImageElement(img, data);
+    Tools.drawingArea.appendChild(img);
+    return img;
+  }
+
+  /**
+    * Updates the image element with new data.
+    */
+  function updateImageElement(imageElement, data) {
+    imageElement.x.baseVal.value = Math.min(data['x2'], data['x']);
+    imageElement.y.baseVal.value = Math.min(data['y2'], data['y']);
+    imageElement.width.baseVal.value = Math.abs(data['x2'] - data['x']);
+    imageElement.height.baseVal.value = Math.abs(data['y2'] - data['y']);
+  }
+
+  /**
+    * Get the name of the current board based on the current URL.
+    * @returns {string} - The name of the current board.
+    */
+  function getCurrentBoardName() {
+    let boardName = window.location.pathname.split('/');
+    boardName = boardName[boardName.length - 1];
+    boardName = boardName.split('#').shift();
+    return boardName;
+  }
+
+  /**
+    * Loads the image from the filesystem to generate a preview while uploading
+    * occurs as well as to get the dimensions of the image.
+    * @param {File} image - The image to preview.
+    * @returns {Promise} - A promise that resolves with the image preview.
+    */
+  async function previewImage(image) {
+    return new Promise((resolve, reject) => {
+      const reader = new FileReader();
+      reader.onload = function (event) {
+        const img = new Image();
+        img.src = event.target.result;
+        img.onload = function () {
+          resolve(img);
+        }
+        img.onerror = function (error) {
+          reject(error);
+        }
+      }
+      reader.readAsDataURL(image);
+    });
+  }
+
+  /**
+    * Uploads an image to the server, draws it on the canvas optimistically.
+    * @param {File} image - The image to upload.
+    * @param {Object} position - The position to draw the image on the canvas.
+    * @param {number} position.x - The x coordinate of the image.
+    * @param {number} position.y - The y coordinate of the image.
+    * @returns {Promise} - A promise that resolves when the image has been uploaded.
+    */
+  async function uploadImage(image, position) {
+    const id = Tools.generateUID();
+    const ImageTool = Tools.list["Image"];
+
+    // Get a preview of the image
+    const previewElement = await previewImage(image);
+
+    const dimensions = {
+      x: previewElement.width,
+      y: previewElement.height
+    };
+
+    // Optimistically draw the image on the canvas before uploading.
+    ImageTool.draw({
+      id,
+      type: "image",
+      src: previewElement.src,
+      opacity: 0.5,
+      x: position.x,
+      y: position.y,
+      x2: position.x + dimensions.x,
+      y2: position.y + dimensions.y,
+    });
+
+    // Upload the image to the server
+    const formData = new FormData();
+    formData.append('image', image);
+    formData.append('id', id);
+    formData.append('position', JSON.stringify(position));
+    formData.append('dimensions', JSON.stringify(dimensions));
+
+    return new Promise((resolve, reject) => {
+      const xhr = new XMLHttpRequest();
+
+      function onError(error) {
+        alert('Failed to upload image :`(')
+        console.log('error: ', error);
+        reject(error);
+      }
+
+      function onProgress(event) {
+        // TODO: Show a loading indicator while the image is uploading.
+        console.log('progress: ', event);
+      }
+
+      function onLoad(response) {
+        if (xhr.status >= 400) {
+          alert('Failed to upload image :`(')
+          reject(response);
+          console.log('onLoad: ', response);
+        }
+        resolve(response);
+      }
+
+      xhr.open('POST', `/image-upload/${getCurrentBoardName()}`, true);
+      xhr.onerror = onError;
+      xhr.onprogress = onProgress;
+      xhr.onload = onLoad;
+      xhr.send(formData);
+    });
+  }
+
+  /**
+    * Handles the drop event on the canvas.
+    * @param {Event} event - The drop event.
+    */
+  function onUploadEvent(event) {
+    const scale = Tools.getScale();
+    const position = {
+      x: event.clientX / scale,
+      y: event.clientY / scale
+    };
+    uploadImage(event.dataTransfer.files[0], position);
+  }
+
+  function onDrop(event) {
+    onUploadEvent(event);
+  }
+
+  /**
+    * Called when the tool is selected.
+    */
+  function onStart() {
+    fileInput.addEventListener('change', onFileInputChange);
+  }
+
+  /**
+    * Called when the tool is deselected.
+    */
+  function onQuit() {
+    fileInput.removeEventListener('change', onFileInputChange);
+  }
+
+  // List of all drag/drop events.
+  const events = [
+    "drag",
+    "dragend",
+    "dragenter",
+    "dragleave",
+    "dragover",
+    "dragstart",
+    "drop"
+  ];
+
+  // Ignore all default handling of drag/drop events on the canvas.
+  function preventDefault(e) {
+    e.preventDefault();
+    e.stopPropagation();
+  }
+
+  events.forEach((eventName) => {
+    drawingArea.addEventListener(eventName, preventDefault, false);
+  });
+
+  drawingArea.addEventListener("drop", onDrop, false);
+
+  var imageTool = {
+    "name": "Image",
+    "shortcut": "i",
+    "listeners": {
+      "press": promptForImage,
+    },
+    "onstart": onStart,
+    "onquit": onQuit,
+    "secondary": null,
+    "draw": draw,
+    "mouseCursor": "crosshair",
+		"icon": "tools/image/icon.svg",
+    "stylesheet": ""
+  };
+  Tools.add(imageTool);
+
+})(); //End of code isolation