From 76b610aa6d41b69eb10caaf419b148a53831989f Mon Sep 17 00:00:00 2001
From: tzutalin <tzu.ta.lin@gmail.com>
Date: Sat, 21 Nov 2015 17:39:40 +0800
Subject: [PATCH] Support openPrevious function

---
 README.md     | 16 +++++++++++++++-
 labelImg.py   | 31 +++++++++++++++++++++++++------
 resources.qrc |  1 +
 3 files changed, 41 insertions(+), 7 deletions(-)

diff --git a/README.md b/README.md
index 6cd3b721..ca7dd9fe 100644
--- a/README.md
+++ b/README.md
@@ -17,7 +17,7 @@ In order to build the resource and assets, you need to install pyqt4-dev-tools:
 `$ sudo apt-get install pyqt4-dev-tools`
 
 ## Usage
-After cloning the code, you should run `make` to generate the resource file.
+After cloning the code, you should run `make all` to generate the resource file.
 
 You can then start annotating by running `./labelImg.py`. For usage
 instructions you can see [Here](https://youtu.be/p0nR2YsCY_U)
@@ -30,6 +30,18 @@ You can also see [ImageNet Utils](https://github.com/tzutalin/ImageNet_Utils) to
 
 You can edit the [data/predefined_classes.txt](https://github.com/tzutalin/labelImg/blob/master/data/predefined_classes.txt) to load pre-defined classes
 
+### General steps from scratch
+
+* Build and launch. `make all; python labelImg.py`
+
+* Click 'Change default saved annotation folder' in Menu/File
+
+* Click 'Open Dir'
+
+* Click 'Create RectBox'
+
+The annotation will be saved to the folder you specifiy
+
 ### Hotkeys
 
 * Ctrl + r : Change the defult target dir which saving annotation files
@@ -39,3 +51,5 @@ You can edit the [data/predefined_classes.txt](https://github.com/tzutalin/label
 * Ctrl + s : Save
 
 * n : Next image
+
+* p : Previou image
diff --git a/labelImg.py b/labelImg.py
index 621d4be7..a2d607e8 100755
--- a/labelImg.py
+++ b/labelImg.py
@@ -142,6 +142,9 @@ class MainWindow(QMainWindow, WindowMixin):
         openNextImg = action('&Next Image', self.openNextImg,
                 'n', 'next', u'Open Next')
 
+        openPrevImg = action('&Prev Image', self.openPrevImg,
+                'p', 'prev', u'Open Prev')
+
         save = action('&Save', self.saveFile,
                 'Ctrl+S', 'save', u'Save labels to file', enabled=False)
         saveAs = action('&Save As', self.saveFileAs,
@@ -278,7 +281,7 @@ class MainWindow(QMainWindow, WindowMixin):
 
         self.tools = self.toolbar('Tools')
         self.actions.beginner = (
-            open, opendir, openNextImg, save, None, create, copy, delete, None,
+            open, opendir, openNextImg, openPrevImg, save, None, create, copy, delete, None,
             zoomIn, zoom, zoomOut, fitWindow, fitWidth)
 
         self.actions.advanced = (
@@ -347,10 +350,6 @@ class MainWindow(QMainWindow, WindowMixin):
 
         self.populateModeActions()
 
-        #self.firstStart = True
-        #if self.firstStart:
-        #    QWhatsThis.enterWhatsThisMode()
-
     ## Support Functions ##
 
     def noShapes(self):
@@ -822,6 +821,19 @@ class MainWindow(QMainWindow, WindowMixin):
         if not self.mayContinue():
             return
 
+        if len(self.mImgList) <= 0:
+            return
+
+        if self.filename is None:
+            return
+
+        currIndex = self.mImgList.index(self.filename)
+        if currIndex -1 >= 0:
+            filename = self.mImgList[currIndex-1]
+
+        if filename:
+            self.loadFile(filename)
+
 
     def openNextImg(self, _value=False):
         # Proceding next image without dialog if having any label
@@ -834,7 +846,14 @@ class MainWindow(QMainWindow, WindowMixin):
 
         if len(self.mImgList) <= 0:
             return
-        filename = self.mImgList.pop(0)
+
+        if self.filename is None:
+            filename = self.mImgList[0]
+        else:
+            currIndex = self.mImgList.index(self.filename)
+            if currIndex + 1 < len(self.mImgList):
+                filename = self.mImgList[currIndex+1]
+
         if filename:
             self.loadFile(filename)
 
diff --git a/resources.qrc b/resources.qrc
index 8875f58e..9ae18234 100644
--- a/resources.qrc
+++ b/resources.qrc
@@ -26,6 +26,7 @@
 <file alias="zoom-out">icons/zoom-out.png</file>
 <file alias="delete">icons/cancel.png</file>
 <file alias="next">icons/next.png</file>
+<file alias="prev">icons/prev.png</file>
 
 </qresource>
 </RCC>