ENH: Add OK/Cancel buttons

skimage/viewer/widgets/core.py

@@ -29,7 +29,7 @@ class BaseWidget(QtGui.QWidget):
 
     plugin = RequiredAttr("Widget is not attached to a Plugin.")
 
-    def __init__(self, name, ptype, callback):
+    def __init__(self, name, ptype=None, callback=None):
         super(BaseWidget, self).__init__()
         self.name = name
         self.ptype = ptype

skimage/viewer/widgets/history.py

@@ -7,16 +7,43 @@ from skimage import io
 from .core import BaseWidget
 
 
-__all__ = ['SaveButtons']
+__all__ = ['OKCancelButtons', 'SaveButtons']
+
+
+class OKCancelButtons(BaseWidget):
+    """Buttons that close the parent plugin.
+
+    OK will replace the original image with the current (filtered) image.
+    Cancel will just close the plugin.
+    """
+    def __init__(self):
+        name = 'OK/Cancel'
+        super(OKCancelButtons, self).__init__(name)
+
+        self.ok = QtGui.QPushButton('OK')
+        self.ok.clicked.connect(self.update_original_image)
+        self.cancel = QtGui.QPushButton('Cancel')
+        self.cancel.clicked.connect(self.close_plugin)
+
+        self.layout = QtGui.QHBoxLayout(self)
+        self.layout.addWidget(self.cancel)
+        self.layout.addWidget(self.ok)
+
+    def update_original_image(self):
+        image = self.plugin.image_viewer.image
+        self.plugin.image_viewer.original_image = image
+        self.plugin.close()
+
+    def close_plugin(self):
+        # Image viewer will restore original image on close.
+        self.plugin.close()
 
 
 class SaveButtons(BaseWidget):
+    """Buttons to save image to io.stack or to a file."""
 
-    def __init__(self, default_format='png'):
-        name = 'Save to:'
-        ptype = None
-        callback = None
-        super(SaveButtons, self).__init__(name, ptype, callback)
+    def __init__(self, name='Save to:', default_format='png'):
+        super(SaveButtons, self).__init__(name)
 
         self.default_format = default_format
 

viewer_examples/plugins/median_filter.py

@@ -3,8 +3,8 @@ from skimage.filter import median_filter
 
 from skimage.viewer import ImageViewer
 from skimage.viewer.widgets import Slider
-from skimage.viewer.widgets.history import SaveButtons
-from skimage.viewer.plugins.overlayplugin import Plugin
+from skimage.viewer.widgets.history import OKCancelButtons, SaveButtons
+from skimage.viewer.plugins.base import Plugin
 
 
 image = data.coins()
@@ -13,6 +13,7 @@ viewer = ImageViewer(image)
 plugin = Plugin(image_filter=median_filter)
 plugin += Slider('radius', 2, 10, value_type='int', update_on='release')
 plugin += SaveButtons()
+plugin += OKCancelButtons()
 
 viewer += plugin
 viewer.show()