feat(Events): a load event to notify when a PDF has finished loading

Closes #3

Author: Merott

AndroidPdfViewer.d.ts

@@ -10,6 +10,24 @@ declare module com.github.barteksc.pdfviewer {
     export interface OnErrorListener {
       onError(throwable: java.lang.Throwable): void;
     }
+
+    interface IOnLoadCompleteListener {
+      /**
+       * Called when the PDF is loaded
+       * @param numPages the number of pages in this PDF file
+       */
+      loadComplete(numPages: number): void;
+    }
+
+    export class OnLoadCompleteListener implements IOnLoadCompleteListener {
+      constructor(implementation: IOnLoadCompleteListener);
+
+      /**
+       * Called when the PDF is loaded
+       * @param numPages the number of pages in this PDF file
+       */
+      loadComplete(numPages: number): void;
+    }
   }
 }
 
@@ -21,5 +39,6 @@ declare class Configurator {
   pages(...pageNumbers: number[]): this;
   enableDoubletap(enable: boolean): this;
   enableSwipe(enable: boolean): this;
+  onLoad(onLoadCompleteListener: pdfviewer.listener.OnLoadCompleteListener): this;
   swipeHorizontal(horizontal: boolean): this;
 }

demo/app/main-page.xml

@@ -3,6 +3,6 @@
  xmlns:pdf="nativescript-pdf-view">
   <StackLayout>
     <Button text="Show Another!" tap="{{ changePDF }}" />
-    <pdf:PDFView src="{{ pdfUrl }}"/>
+    <pdf:PDFView src="{{ pdfUrl }}" load="{{ onLoad }}"/>
   </StackLayout>
 </Page>

demo/app/main-view-model.ts

@@ -19,5 +19,9 @@ export class HelloWorldModel extends Observable {
     this.set('pdfUrl', this.pdfUrls[(this.current + 1) % this.pdfUrls.length]);
   }
 
+  public onLoad() {
+    alert('Loaded PDF!');
+  }
+
   private current = 0;
 }

src/plugin.android.ts

@@ -9,6 +9,16 @@ export class PDFView extends common.PDFView {
   private promise: Promise<any>;
   private tempFolder = fs.knownFolders.temp().getFolder('PDFViewer.temp/');
 
+  private onLoadHandler = (() => {
+    const pdfViewRef = new WeakRef(this);
+
+    return new pdfviewer.listener.OnLoadCompleteListener({
+      loadComplete: (numPages) => {
+        common.PDFView.notifyOfEvent(common.PDFView.loadEvent, pdfViewRef);
+      }
+    });
+  })();
+
   public get android() {
     return this._android;
   }
@@ -17,12 +27,12 @@ export class PDFView extends common.PDFView {
     this._android = value;
   }
 
-  public load(src: string) {
+  public loadPDF(src: string) {
     if (!src || !this.android) {
       return;
     }
 
-    // reset any previous promise since we've called load again
+    // reset any previous promise since we've called loadPDF again
     this.promise = void 0;
 
     if (src.indexOf('://') === -1) {
@@ -36,6 +46,7 @@ export class PDFView extends common.PDFView {
 
     this.android
       .fromUri(uri)
+      .onLoad(this.onLoadHandler)
       .load();
   }
 
@@ -48,7 +59,7 @@ export class PDFView extends common.PDFView {
         .getFile(url, `${this.tempFolder.path}/${java.util.UUID.randomUUID()}`)
         .then(file => {
           if (this.promise === promise) {  // make sure we haven't switched
-            this.load(file.path);
+            this.loadPDF(file.path);
           }
         }).catch(error => {
           console.error(error);
@@ -58,6 +69,6 @@ export class PDFView extends common.PDFView {
 
   private _createUI() {
     this._android = new pdfviewer.PDFView(this._context, void 0);
-    this.load(this.src);
+    this.loadPDF(this.src);
   }
 }

src/plugin.common.ts

@@ -8,16 +8,26 @@ export abstract class PDFView extends view.View {
   private static srcProperty = new Property(
     'src', 'PdfView', new proxy.PropertyMetadata(''));
 
+  public static loadEvent = 'load';
+
+  public static notifyOfEvent(eventName: string, pdfViewRef: WeakRef<PDFView>) {
+    const viewer = pdfViewRef.get();
+
+    if (viewer) {
+      viewer.notify({ eventName, object: viewer });
+    }
+  }
+
   public get src(): string {
     return this._getValue(PDFView.srcProperty);
   }
 
   public set src(src: string) {
     this._setValue(PDFView.srcProperty, src);
-    this.load(src);
+    this.loadPDF(src);
   }
 
-  public abstract load(src: string);
+  public abstract loadPDF(src: string);
 }
 
 try {

src/plugin.ios.ts

@@ -4,11 +4,12 @@ import * as common from './plugin.common';
 
 export class PDFView extends common.PDFView {
   private _ios: UIWebView;
+  private delegate: PDFViewDelegate;
 
   constructor() {
     super();
     this.init();
-    this.load(this.src);
+    this.loadPDF(this.src);
   }
 
   public get ios() {
@@ -19,7 +20,7 @@ export class PDFView extends common.PDFView {
     this._ios = value;
   }
 
-  public load(src: string) {
+  public loadPDF(src: string) {
     if (!src) {
       return;
     }
@@ -36,13 +37,40 @@ export class PDFView extends common.PDFView {
     this.ios.loadRequest(urlRequest);
   }
 
+  public onLoaded() {
+    super.onLoaded();
+    this._ios.delegate = this.delegate;
+  }
+
+  public onUnloaded() {
+    this._ios.delegate = null;
+    super.onUnloaded();
+  }
+
   private init() {
     this.ios = new UIWebView(UIScreen.mainScreen().bounds);
+    this.delegate = PDFViewDelegate.initWithOwner(new WeakRef(this));
 
     this.ios.autoresizingMask =
       UIViewAutoresizing.UIViewAutoresizingFlexibleWidth |
       UIViewAutoresizing.UIViewAutoresizingFlexibleHeight;
 
     this.ios.scalesPageToFit = true;
   }
+}
+
+class PDFViewDelegate extends NSObject implements UIWebViewDelegate {
+  public static ObjCProtocols = [UIWebViewDelegate];
+
+  public static initWithOwner(owner: WeakRef<PDFView>): PDFViewDelegate {
+    let delegate = <PDFViewDelegate>PDFViewDelegate.new();
+    delegate.owner = owner;
+    return delegate;
+  }
+
+  public webViewDidFinishLoad(webView: UIWebView) {
+    return common.PDFView.notifyOfEvent(common.PDFView.loadEvent, this.owner);
+  }
+
+  private owner: WeakRef<PDFView>;
 }