From d3edd350f9baa5d771b12492e3aba859ef7956e6 Mon Sep 17 00:00:00 2001
From: Tony S Yu <tsyu80@gmail.com>
Date: Sun, 23 Dec 2012 16:19:03 -0800
Subject: [PATCH] ENH: Add open and save menu actions

---
 skimage/viewer/utils/dialogs.py   | 26 +++++++++++++++++++++++++
 skimage/viewer/viewers/core.py    | 32 ++++++++++++++++++++++++++++++-
 skimage/viewer/widgets/history.py | 10 +++-------
 3 files changed, 60 insertions(+), 8 deletions(-)
 create mode 100644 skimage/viewer/utils/dialogs.py

diff --git a/skimage/viewer/utils/dialogs.py b/skimage/viewer/utils/dialogs.py
new file mode 100644
index 00000000..849fcad7
--- /dev/null
+++ b/skimage/viewer/utils/dialogs.py
@@ -0,0 +1,26 @@
+import os
+
+try:
+    from PyQt4 import QtGui
+except ImportError:
+    print("Could not import PyQt4 -- skimage.viewer not available.")
+
+
+def open_file_dialog(default_format='png'):
+    """Return user-selected file path."""
+    filename = str(QtGui.QFileDialog.getOpenFileName())
+    if len(filename) == 0:
+        return None
+    return filename
+
+
+def save_file_dialog(default_format='png'):
+    """Return user-selected file path."""
+    filename = str(QtGui.QFileDialog.getSaveFileName())
+    if len(filename) == 0:
+        return None
+    #TODO: io plugins should assign default image formats
+    basename, ext = os.path.splitext(filename)
+    if not ext:
+        filename = '%s.%s' % (filename, default_format)
+    return filename
diff --git a/skimage/viewer/viewers/core.py b/skimage/viewer/viewers/core.py
index 1c369707..83ef65a3 100644
--- a/skimage/viewer/viewers/core.py
+++ b/skimage/viewer/viewers/core.py
@@ -8,9 +8,11 @@ except ImportError:
     QMainWindow = object  # hack to prevent nosetest and autodoc errors
     print("Could not import PyQt4 -- skimage.viewer not available.")
 
+from skimage import io
 from skimage.util.dtype import dtype_range
 from .. import utils
 from ..widgets import Slider
+from ..utils import dialogs
 
 
 __all__ = ['ImageViewer', 'CollectionViewer']
@@ -58,7 +60,11 @@ class ImageViewer(QMainWindow):
         self.setWindowTitle("Image Viewer")
 
         self.file_menu = QtGui.QMenu('&File', self)
-        self.file_menu.addAction('&Quit', self.close,
+        self.file_menu.addAction('Open file', self.open_file,
+                                 QtCore.Qt.CTRL + QtCore.Qt.Key_O)
+        self.file_menu.addAction('Save to file', self.save_to_file,
+                                 QtCore.Qt.CTRL + QtCore.Qt.Key_S)
+        self.file_menu.addAction('Quit', self.close,
                                  QtCore.Qt.CTRL + QtCore.Qt.Key_Q)
         self.menuBar().addMenu(self.file_menu)
 
@@ -101,6 +107,30 @@ class ImageViewer(QMainWindow):
         plugin.attach(self)
         return self
 
+    def open_file(self):
+        """Open image file and display in viewer."""
+        filename = dialogs.open_file_dialog()
+        if filename is None:
+            return
+        image = io.imread(filename)
+        self.original_image = image     # update saved image
+        self.image = image              # update displayed image
+
+    def save_to_file(self):
+        """Save current image to file.
+
+        The current behavior is not ideal: It saves the image displayed on
+        screen, so all images will be converted to RGB, and the image size is
+        not preserved (resizing the viewer window will alter the size of the
+        saved image).
+        """
+        filename = dialogs.save_file_dialog()
+        if filename is None:
+            return
+        extent = self.ax.get_window_extent()
+        extent = extent.transformed(self.fig.dpi_scale_trans.inverted())
+        self.fig.savefig(filename, bbox_inches=extent)
+
     def closeEvent(self, event):
         self.close()
 
diff --git a/skimage/viewer/widgets/history.py b/skimage/viewer/widgets/history.py
index ce87f9ac..e3aaa938 100644
--- a/skimage/viewer/widgets/history.py
+++ b/skimage/viewer/widgets/history.py
@@ -1,4 +1,3 @@
-import os
 from textwrap import dedent
 
 try:
@@ -11,6 +10,7 @@ import numpy as np
 import skimage
 from skimage import io
 from .core import BaseWidget
+from ..utils import dialogs
 
 
 __all__ = ['OKCancelButtons', 'SaveButtons']
@@ -84,13 +84,9 @@ class SaveButtons(BaseWidget):
         notify(msg)
 
     def save_to_file(self):
-        filename = str(QtGui.QFileDialog.getSaveFileName())
-        if len(filename) == 0:
+        filename = dialogs.save_file_dialog()
+        if filename is None:
             return
-        #TODO: io plugins should assign default image formats
-        basename, ext = os.path.splitext(filename)
-        if not ext:
-            filename = '%s.%s' % (filename, self.default_format)
         image = self.plugin.filtered_image
         if image.dtype == np.bool:
             #TODO: This check/conversion should probably be in `imsave`.