添加注释

Author: DingProg

lib/DrawImageUtils.dart

@@ -13,6 +13,7 @@ class DrawImageUtils {
   static Future<flutterUi.Image> drawFrameImage(
       String originImageUrl, String frameImageUrl) {
     Completer<flutterUi.Image> completer = new Completer<flutterUi.Image>();
+    //加载图片
     Future.wait([
       OriginImage.getInstance().loadImage(originImageUrl),
       ImageLoader.load(frameImageUrl)
@@ -45,6 +46,8 @@ class DrawImageUtils {
               originHeight),
           Rect.fromLTWH(0, 0, width.toDouble(), height.toDouble()),
           paint);
+
+      //裁剪图片
       paint.blendMode = BlendMode.dstIn;
       canvas.drawImage(result[1], Offset(0, 0), paint);
       recorder.endRecording().toImage(width, height).then((image) {
@@ -62,6 +65,7 @@ class DrawImageUtils {
     Completer<flutterUi.Image> completer = new Completer<flutterUi.Image>();
     Future.wait([
       ImageLoader.load(maskImage),
+      //获取裁剪图片
       drawFrameImage(originImageUrl, frameImageUrl)
     ]).then((result) {
       Paint paint = new Paint();
@@ -71,13 +75,16 @@ class DrawImageUtils {
       int width = result[0].width;
       int height = result[0].height;
 
+      //合成
       canvas.drawImage(result[1], offset, paint);
       canvas.drawImageRect(
           result[0],
           Rect.fromLTWH(
               0, 0, result[0].width.toDouble(), result[0].height.toDouble()),
           Rect.fromLTWH(0, 0, width.toDouble(), height.toDouble()),
           paint);
+
+      //生成图片
       recorder.endRecording().toImage(width, height).then((image) {
         completer.complete(image);
       });

lib/DrawPIPWidget.dart

@@ -34,7 +34,8 @@ class DrawPIPState extends State<DrawPIPWidget> {
         height: _width,
         child: new Stack(
           children: <Widget>[
-            getBackgroundImage(),
+            getBackgroundImage(), //底部高斯模糊图片
+            //合成后的效果图片，使用CustomPaint 绘制出来
             CustomPaint(
                 painter: DrawPainter(widget._image),
                 size: Size(_width, _width)),

lib/PreviewImagePage.dart

@@ -27,7 +27,7 @@ class PreviewImageWidget extends StatefulWidget {
 }
 
 class PreviewImageState extends State<PreviewImageWidget> {
-  final GlobalKey globalKey = new GlobalKey();
+  final GlobalKey pipCaptureKey = new GlobalKey();
 
   List<String> _listImageIcon = [];
   List<Offset> _imageOffset = [];
@@ -82,15 +82,15 @@ class PreviewImageState extends State<PreviewImageWidget> {
           getBottomListView()
         ]))),
         floatingActionButton: FloatingActionButton(
-          onPressed: _capturePng,
+          onPressed: _captureImage,
           tooltip: 'save',
           child: Icon(Icons.save),
         ));
   }
 
   Widget getPIPImageWidget() {
     return RepaintBoundary(
-      key: globalKey,
+      key: pipCaptureKey,
       child: new Center(child: new DrawPIPWidget(_originImage, _image)),
     );
   }
@@ -138,9 +138,9 @@ class PreviewImageState extends State<PreviewImageWidget> {
         padding: EdgeInsets.all(20), height: 140, child: listView);
   }
 
-  Future<void> _capturePng() async {
+  Future<void> _captureImage() async {
     RenderRepaintBoundary boundary =
-        globalKey.currentContext.findRenderObject();
+        pipCaptureKey.currentContext.findRenderObject();
     var image = await boundary.toImage();
     ByteData byteData = await image.toByteData(format: ImageByteFormat.png);
     Uint8List pngBytes = byteData.buffer.asUint8List();
@@ -157,17 +157,17 @@ class PreviewImageState extends State<PreviewImageWidget> {
       barrierDismissible: false,
       builder: (BuildContext context) {
         return AlertDialog(
-          title: Text('Save success'),
+          title: Text('PIP Path'),
           content: SingleChildScrollView(
             child: ListBody(
               children: <Widget>[
-                Text('Image is save in ${path}'),
+                Text('Image is save in $path'),
               ],
             ),
           ),
           actions: <Widget>[
             FlatButton(
-              child: Text('exit'),
+              child: Text('退出'),
               onPressed: () {
                 Navigator.of(context).pop();
               },