client/file-dropper: add URL support

client/css/forms.styl

@@ -342,14 +342,26 @@ input::-moz-focus-inner
 /*
  * File dropper
  */
-.file-dropper
-    background: $window-color
-    border: 3px dashed #eee
-    padding: 0.3em 0.5em
-    line-height: 140%
-    text-align: center
-    cursor: pointer
-    word-wrap: break-word
+.file-dropper-holder
+    display: flex
+    flex-wrap: wrap
+    .file-dropper
+        display: block
+        width: 100%
+        background: $window-color
+        border: 3px dashed #eee
+        padding: 0.3em 0.5em
+        line-height: 140%
+        text-align: center
+        cursor: pointer
+        word-wrap: break-word
+    input
+        margin-top: 0.5em
+        width: auto
+        flex: 1
+    button
+        margin-top: 0.5em
+        width: 8em
 
 input[type=file]:disabled+.file-dropper
     cursor: default

client/html/file_dropper.tpl

@@ -9,4 +9,8 @@
         <br/>
         Or just click on this box.
     </label>
+    <% if (ctx.allowUrls) { %>
+        <input type='text' name='url' placeholder='Alternatively, paste an URL here.'/>
+        <button>Add URL</button>
+    <% } %>
 </div>

client/js/controls/file_dropper_control.js

@@ -12,11 +12,14 @@ class FileDropperControl extends events.EventTarget {
         this._options = options;
         const source = template({
             allowMultiple: this._options.allowMultiple,
+            allowUrls: this._options.allowUrls,
             id: 'file-' + Math.random().toString(36).substring(7),
         });
 
         this._dropperNode = source.querySelector('.file-dropper');
-        this._fileInputNode = source.querySelector('input');
+        this._urlInputNode = source.querySelector('input[type=text]');
+        this._urlConfirmButtonNode = source.querySelector('button');
+        this._fileInputNode = source.querySelector('input[type=file]');
         this._fileInputNode.style.display = 'none';
         this._fileInputNode.multiple = this._options.allowMultiple || false;
 
@@ -32,6 +35,11 @@ class FileDropperControl extends events.EventTarget {
         this._fileInputNode.addEventListener(
             'change', e => this._evtFileChange(e));
 
+        if (this._urlInputNode) {
+            this._urlConfirmButtonNode.addEventListener(
+                'click', e => this._evtUrlConfirm(e));
+        }
+
         this._originalHtml = this._dropperNode.innerHTML;
         views.replaceContent(target, source);
     }
@@ -51,8 +59,18 @@ class FileDropperControl extends events.EventTarget {
             new CustomEvent('fileadd', {detail: {files: files}}));
     }
 
-    _evtFileChange(e) {
-        this._resolve(e.target.files);
+    _emitUrls(urls) {
+        urls = Array.from(urls).map(url => url.trim());
+        for (let url of urls) {
+            if (!url) {
+                return;
+            }
+            if (!url.match(/^https:?\/\/[^.]+\..+$/)) {
+                window.alert(`"${url}" does not look like a valid URL.`);
+                return;
+            }
+        }
+        this.dispatchEvent(new CustomEvent('urladd', {detail: {urls: urls}}));
     }
 
     _evtDragEnter(e) {
@@ -86,6 +104,13 @@ class FileDropperControl extends events.EventTarget {
         }
         this._emitFiles(e.dataTransfer.files);
     }
+
+    _evtUrlConfirm(e) {
+        e.preventDefault();
+        this._dropperNode.classList.remove('active');
+        this._emitUrls(this._urlInputNode.value.split(/[\r\n]/));
+        this._urlInputNode.value = '';
+    }
 }
 
 module.exports = FileDropperControl;