Add ctrl+v hotkey to be able copy the bounding boxes from the previous image to the current (#627)

* Add previous bounding boxes code

* Create method to avoid repeated code

* Fix text in the action copyprevbounding

* Add description for different languages

labelImg.py

@@ -210,6 +210,9 @@ class MainWindow(QMainWindow, WindowMixin):
         opendir = action(getStr('openDir'), self.openDirDialog,
                          'Ctrl+u', 'open', getStr('openDir'))
         
+        copyPrevBounding = action(getStr('copyPrevBounding'), self.copyPreviousBoundingBoxes,
+                         'Ctrl+v', 'paste', getStr('copyPrevBounding'))
+
         changeSavedir = action(getStr('changeSaveDir'), self.changeSavedirDialog,
                                'Ctrl+r', 'open', getStr('changeSavedAnnotationDir'))
 
@@ -380,7 +383,7 @@ class MainWindow(QMainWindow, WindowMixin):
         self.displayLabelOption.triggered.connect(self.togglePaintLabelsOption)
 
         addActions(self.menus.file,
-                   (open, opendir, changeSavedir, openAnnotation, self.menus.recentFiles, save, save_format, saveAs, close, resetAll, deleteImg, quit))
+                   (open, opendir, copyPrevBounding, changeSavedir, openAnnotation, self.menus.recentFiles, save, save_format, saveAs, close, resetAll, deleteImg, quit))
         addActions(self.menus.help, (help, showInfo))
         addActions(self.menus.view, (
             self.autoSaving,
@@ -1061,11 +1064,23 @@ class MainWindow(QMainWindow, WindowMixin):
             self.paintCanvas()
             self.addRecentFile(self.filePath)
             self.toggleActions(True)        
+            self.showXmlBoundingBoxes(filePath)
 
-            # Label xml file and show bound box according to its filename
+            self.setWindowTitle(__appname__ + ' ' + filePath)
+
+            # Default : select last item if there is at least one item
+            if self.labelList.count():
+                self.labelList.setCurrentItem(self.labelList.item(self.labelList.count()-1))
+                self.labelList.item(self.labelList.count()-1).setSelected(True)
+
+            self.canvas.setFocus(True)
+            return True
+        return False
+
+    def showXmlBoundingBoxes(self, filePath):
         if self.defaultSaveDir is not None:
             basename = os.path.basename(
-                    os.path.splitext(self.filePath)[0])
+                os.path.splitext(filePath)[0])
             xmlPath = os.path.join(self.defaultSaveDir, basename + XML_EXT)
             txtPath = os.path.join(self.defaultSaveDir, basename + TXT_EXT)
 
@@ -1084,17 +1099,6 @@ class MainWindow(QMainWindow, WindowMixin):
             elif os.path.isfile(txtPath):
                 self.loadYOLOTXTByFilename(txtPath)
 
-            self.setWindowTitle(__appname__ + ' ' + filePath)
-
-            # Default : select last item if there is at least one item
-            if self.labelList.count():
-                self.labelList.setCurrentItem(self.labelList.item(self.labelList.count()-1))
-                self.labelList.item(self.labelList.count()-1).setSelected(True)
-
-            self.canvas.setFocus(True)
-            return True
-        return False
-
     def resizeEvent(self, event):
         if self.canvas and not self.image.isNull()\
            and self.zoomMode != self.MANUAL_ZOOM:
@@ -1494,6 +1498,13 @@ class MainWindow(QMainWindow, WindowMixin):
         self.loadLabels(shapes)
         self.canvas.verified = tYoloParseReader.verified
 
+    def copyPreviousBoundingBoxes(self):
+        currIndex = self.mImgList.index(self.filePath)
+        prevFilePath = self.mImgList[currIndex - 1]
+        
+        self.showXmlBoundingBoxes(prevFilePath)
+        self.saveFile()
+        
     def togglePaintLabelsOption(self):
         for shape in self.canvas.shapes:
             shape.paintLabel = self.displayLabelOption.isChecked()

resources/strings/strings-zh-CN.properties

@@ -31,6 +31,7 @@ save=保存
 saveAs=另存为
 fitWinDetail=缩放到当前窗口大小
 openDir=打开目录
+copyPrevBounding=复制当前图像中的上一个边界框
 showHide=显示/隐藏标签
 changeSaveFormat=更改存储格式
 shapeFillColor=填充颜色

resources/strings/strings-zh-TW.properties

@@ -31,6 +31,7 @@ save=儲存
 saveAs=另存為
 fitWinDetail=縮放到窗口一樣
 openDir=開啟目錄
+copyPrevBounding=複製當前圖像中的上一個邊界框
 showHide=顯示/隱藏標籤
 changeSaveFormat=更改儲存格式
 shapeFillColor=填充顏色

resources/strings/strings.properties

@@ -3,6 +3,7 @@ openFileDetail=Open image or label file
 quit=Quit
 quitApp=Quit application
 openDir=Open Dir
+copyPrevBounding=Copy previous Bounding Boxes in the current image 
 changeSavedAnnotationDir=Change default saved Annotation dir
 openAnnotation=Open Annotation
 openAnnotationDetail=Open an annotation file