Merge pull request #575 from tonysyu/feature/viewer-linking

Linked image viewers and docked plugins

skimage/viewer/plugins/base.py

@@ -1,9 +1,12 @@
 """
 Base class for Plugins that interact with ImageViewer.
 """
-from ..qt import QtGui
-from ..qt.QtCore import Qt
+from warnings import warn
 
+import numpy as np
+
+from ..qt import QtGui
+from ..qt.QtCore import Qt, Signal
 from ..utils import RequiredAttr, init_qtapp
 
 
@@ -71,14 +74,24 @@ class Plugin(QtGui.QDialog):
     name = 'Plugin'
     image_viewer = RequiredAttr("%s is not attached to ImageViewer" % name)
 
-    def __init__(self, image_filter=None, height=0, width=400, useblit=True):
+    # Signals used when viewers are linked to the Plugin output.
+    image_changed = Signal(np.ndarray)
+    _started = Signal(int)
+
+    def __init__(self, image_filter=None, height=0, width=400, useblit=True,
+                 dock='bottom'):
         init_qtapp()
         super(Plugin, self).__init__()
 
+        self.dock = dock
+
         self.image_viewer = None
         # If subclass defines `image_filter` method ignore input.
         if not hasattr(self, 'image_filter'):
             self.image_filter = image_filter
+        elif image_filter is not None:
+            warn("If the Plugin class defines an `image_filter` method, "
+                 "then the `image_filter` argument is ignored.")
 
         self.setWindowTitle(self.name)
         self.layout = QtGui.QGridLayout(self)
@@ -109,7 +122,7 @@ class Plugin(QtGui.QDialog):
         self.image_viewer = image_viewer
         self.image_viewer.plugins.append(self)
         #TODO: Always passing image as first argument may be bad assumption.
-        self.arguments.append(self.image_viewer.original_image)
+        self.arguments = [self.image_viewer.original_image]
 
         # Call filter so that filtered image matches widget values
         self.filter_image()
@@ -155,12 +168,22 @@ class Plugin(QtGui.QDialog):
         kwargs = dict([(name, self._get_value(a))
                        for name, a in self.keyword_arguments.items()])
         filtered = self.image_filter(*arguments, **kwargs)
+
         self.display_filtered_image(filtered)
+        self.image_changed.emit(filtered)
 
     def _get_value(self, param):
         # If param is a widget, return its `val` attribute.
         return param if not hasattr(param, 'val') else param.val
 
+    def _update_original_image(self, image):
+        """Update the original image argument passed to the filter function.
+
+        This method is called by the viewer when the original image is updated.
+        """
+        self.arguments[0] = image
+        self.filter_image()
+
     @property
     def filtered_image(self):
         """Return filtered image."""
@@ -183,6 +206,17 @@ class Plugin(QtGui.QDialog):
         """
         setattr(self, name, value)
 
+    def show(self, main_window=True):
+        """Show plugin."""
+        super(Plugin, self).show()
+        self.activateWindow()
+        self.raise_()
+
+        # Emit signal with x-hint so new windows can be displayed w/o overlap.
+        size = self.frameGeometry()
+        x_hint = size.x() + size.width()
+        self._started.emit(x_hint)
+
     def closeEvent(self, event):
         """On close disconnect all artists and events from ImageViewer.