Improvements to link editor

CHANGES.md

@@ -14,6 +14,10 @@ v0.9.0 (unreleased)
 
 * Improve support for spectral cubes. [#1075]
 
+* Allow link functions/helpers to define a category using the ``category=``
+  argument (which defaults to ``General``), and make it possible to filter
+  by category in the link editor. [#1141]
+
 * Only show the 'waiting' cursor when glue is doing something. [#1097]
 
 * Make sure that the scatter layer artist style editor is shown when overplotting

glue/config.py

@@ -466,8 +466,10 @@ class LinkFunctionRegistry(Registry):
     """Stores functions to convert between quantities
 
     The members properety is a list of (function, info_string,
-    output_labels) namedtuples. `info_string` is describes what the
-    function does. `output_labels` is a list of names for each output.
+    output_labels) namedtuples. ``info_string`` describes what the
+    function does. ``output_labels`` is a list of names for each output.
+    ``category`` is a category in which the link funtion will appear (defaults
+    to 'General').
 
     New link functions can be registered via
 
@@ -478,18 +480,13 @@ def degrees2arcsec(degrees):
 
     Link functions are expected to receive and return numpy arrays
     """
-    item = namedtuple('LinkFunction', 'function info output_labels')
+    item = namedtuple('LinkFunction', 'function info output_labels category')
 
-    def default_members(self):
-        from glue.core import link_helpers
-        return list(self.item(l, "", l.output_args)
-                    for l in link_helpers.__LINK_FUNCTIONS__)
-
-    def __call__(self, info="", output_labels=None):
+    def __call__(self, info="", output_labels=None, category='General'):
         out = output_labels or []
 
         def adder(func):
-            self.add(self.item(func, info, out))
+            self.add(self.item(func, info, out, category))
             return func
         return adder
 
@@ -516,7 +513,8 @@ class LinkHelperRegistry(Registry):
     The members property is a list of (object, info_string,
     input_labels) tuples. `Object` is the link helper. `info_string`
     describes what `object` does. `input_labels` is a list labeling
-    the inputs.
+    the inputs. ``category`` is a category in which the link funtion will appear
+    (defaults to 'General').
 
     Each link helper takes a list of ComponentIDs as inputs, and
     returns an iterable object (e.g. list) of ComponentLinks.
@@ -529,16 +527,11 @@ def new_helper(degree, arcsecond):
             return [ComponentLink([degree], arcsecond, using=lambda d: d*3600),
                     ComponentLink([arcsecond], degree, using=lambda a: a/3600)]
     """
-    item = namedtuple('LinkHelper', 'helper info input_labels')
-
-    def default_members(self):
-        from glue.core.link_helpers import __LINK_HELPERS__ as helpers
-        return list(self.item(l, l.info_text, l.input_args)
-                    for l in helpers)
+    item = namedtuple('LinkHelper', 'helper info input_labels category')
 
-    def __call__(self, info, input_labels):
+    def __call__(self, info, input_labels, category='General'):
         def adder(func):
-            self.add(self.item(func, info, input_labels))
+            self.add(self.item(func, info, input_labels, category))
             return func
         return adder
 

glue/core/link_helpers.py

@@ -2,18 +2,14 @@
 This module provides several classes and LinkCollection classes to
 assist in linking data.
 
-The functions in this class (and stored in the __LINK_FUNCTIONS__
-list) define common coordinate transformations. They are meant to be
-used for the `using` parameter in
-:class:`glue.core.component_link.ComponentLink` instances.
-
 The :class:`LinkCollection` class and its sublcasses are factories to create
 multiple ComponentLinks easily. They are meant to be passed to
 :meth:`~glue.core.data_collection.DataCollection.add_link()`
 """
 
 from __future__ import absolute_import, division, print_function
 
+from glue.config import link_function
 from glue.external import six
 from glue.core.data import ComponentID
 from glue.core.component_link import ComponentLink
@@ -22,27 +18,19 @@
 __all__ = ['LinkCollection', 'LinkSame', 'LinkTwoWay', 'MultiLink',
            'LinkAligned']
 
-__LINK_FUNCTIONS__ = []
-__LINK_HELPERS__ = []
-
 
+@link_function("Link conceptually identical components",
+               output_labels=['y'])
 def identity(x):
     return x
-identity.output_args = ['y']
 
 
+@link_function("Convert between linear measurements and volume",
+               output_labels=['volume'])
 def lengths_to_volume(width, height, depth):
-    """Compute volume from linear measurements of a box"""
-    # included for demonstration purposes
     return width * height * depth
 
 
-lengths_to_volume.output_args = ['area']
-
-__LINK_FUNCTIONS__.append(identity)
-__LINK_FUNCTIONS__.append(lengths_to_volume)
-
-
 class PartialResult(object):
 
     def __init__(self, func, index, name_prefix=""):

glue/dialogs/link_editor/qt/link_equation.py

@@ -2,23 +2,30 @@
 
 import os
 from inspect import getargspec
-from collections import OrderedDict
 
 from qtpy import QtWidgets
 from qtpy import PYSIDE
 from glue import core
+from glue.config import link_function, link_helper
 from glue.utils import nonpartial
-from glue.utils.qt import load_ui, messagebox_on_error
+from glue.utils.qt import load_ui, messagebox_on_error, update_combobox
+from glue.utils.qt.widget_properties import CurrentComboTextProperty, CurrentComboDataProperty
 
 __all__ = ['LinkEquation']
 
 
+def get_function_name(item):
+    if hasattr(item, 'display') and item.display is not None:
+        return item.display
+    else:
+        return item.__name__
+
+
 def function_label(function):
     """ Provide a label for a function
 
     :param function: A member from the glue.config.link_function registry
     """
-    name = function.function.__name__
     args = getargspec(function.function)[0]
     args = ', '.join(args)
     output = function.output_labels
@@ -114,19 +121,13 @@ class LinkEquation(QtWidgets.QWidget):
        widget = LinkEquation()
     """
 
+    category = CurrentComboTextProperty('_ui.category')
+    function = CurrentComboDataProperty('_ui.function')
+
     def __init__(self, parent=None):
         super(LinkEquation, self).__init__(parent)
-        from glue.config import link_function, link_helper
 
         # Set up mapping of function/helper name -> function/helper tuple. For the helpers, we use the 'display' name if available.
-        def get_name(item):
-            if hasattr(item, 'display') and item.display is not None:
-                return item.display
-            else:
-                return item.__name__
-        f = [f for f in link_function.members if len(f.output_labels) == 1]
-        self._functions = OrderedDict((get_name(l[0]), l) for l in
-                                      f + link_helper.members)
         self._argument_widgets = []
         self.spacer = None
         self._output_widget = ArgumentWidget("")
@@ -140,6 +141,8 @@ def get_name(item):
         self.setLayout(l)
 
         self._init_widgets()
+        self._populate_category_combo()
+        self.category = 'General'
         self._populate_function_combo()
         self._connect()
         self._setup_editor()
@@ -189,27 +192,6 @@ def signature(self, inout):
             a.component_id = i
         self._output_widget.component_id = out
 
-    @property
-    def function(self):
-        """ The currently-selected function
-
-        :rtype: A function or helper tuple
-        """
-        fname = str(self._ui.function.currentText())
-        func = self._functions[fname]
-        return func
-
-    @function.setter
-    def function(self, val):
-        if hasattr(val[0], 'display') and val[0].display is not None:
-            name = val[0].display
-        else:
-            name = val[0].__name__
-        pos = self._ui.function.findText(name)
-        if pos < 0:
-            raise KeyError("No function or helper found %s" % [val])
-        self._ui.function.setCurrentIndex(pos)
-
     @messagebox_on_error("Failed to create links")
     def links(self):
         """ Create ComponentLinks from the state of the widget
@@ -245,6 +227,7 @@ def _connect(self):
         signal.connect(nonpartial(self._setup_editor))
         signal.connect(nonpartial(self._update_add_enabled))
         self._output_widget.editor.textChanged.connect(nonpartial(self._update_add_enabled))
+        self._ui.category.currentIndexChanged.connect(self._populate_function_combo)
 
     def clear_inputs(self):
         for w in self._argument_widgets:
@@ -312,8 +295,13 @@ def _clear_input_canvas(self):
 
         self._argument_widgets = []
 
+    def _populate_category_combo(self):
+        f = [f for f in link_function.members if len(f.output_labels) == 1]
+        categories = sorted(set(l.category for l in f + link_helper.members))
+        update_combobox(self._ui.category, list(zip(categories, categories)))
+
     def _populate_function_combo(self):
         """ Add name of functions to function combo box """
-        self._ui.function.clear()
-        for f in self._functions:
-            self._ui.function.addItem(f)
+        f = [f for f in link_function.members if len(f.output_labels) == 1]
+        functions = ((get_function_name(l[0]), l) for l in f + link_helper.members if l.category == self.category)
+        update_combobox(self._ui.function, functions)

glue/dialogs/link_editor/qt/link_equation.ui

@@ -6,8 +6,8 @@
    <rect>
     <x>0</x>
     <y>0</y>
-    <width>466</width>
-    <height>605</height>
+    <width>714</width>
+    <height>336</height>
    </rect>
   </property>
   <property name="minimumSize">
@@ -24,36 +24,59 @@
     <number>4</number>
    </property>
    <item>
-    <layout class="QVBoxLayout" name="verticalLayout" stretch="0,0,0,0,8,8,0">
+    <layout class="QVBoxLayout" name="verticalLayout" stretch="0,0,0,8,8,0">
      <item>
-      <widget class="QLabel" name="top_label">
-       <property name="font">
-        <font>
-         <pointsize>14</pointsize>
-         <weight>50</weight>
-         <bold>false</bold>
-        </font>
-       </property>
-       <property name="text">
-        <string>Select a function</string>
-       </property>
-       <property name="scaledContents">
-        <bool>false</bool>
-       </property>
-       <property name="alignment">
-        <set>Qt::AlignCenter</set>
-       </property>
-      </widget>
-     </item>
-     <item>
-      <widget class="QComboBox" name="function">
-       <property name="toolTip">
-        <string>Select a translation function to use</string>
-       </property>
-       <property name="sizeAdjustPolicy">
-        <enum>QComboBox::AdjustToMinimumContentsLength</enum>
-       </property>
-      </widget>
+      <layout class="QHBoxLayout" name="horizontalLayout_6">
+       <item>
+        <widget class="QLabel" name="label">
+         <property name="text">
+          <string>Category:</string>
+         </property>
+        </widget>
+       </item>
+       <item>
+        <widget class="QComboBox" name="category"/>
+       </item>
+       <item>
+        <spacer name="horizontalSpacer_2">
+         <property name="orientation">
+          <enum>Qt::Horizontal</enum>
+         </property>
+         <property name="sizeType">
+          <enum>QSizePolicy::Fixed</enum>
+         </property>
+         <property name="sizeHint" stdset="0">
+          <size>
+           <width>40</width>
+           <height>20</height>
+          </size>
+         </property>
+        </spacer>
+       </item>
+       <item>
+        <widget class="QLabel" name="label_2">
+         <property name="text">
+          <string>Function:</string>
+         </property>
+        </widget>
+       </item>
+       <item>
+        <widget class="QComboBox" name="function">
+         <property name="sizePolicy">
+          <sizepolicy hsizetype="Expanding" vsizetype="Fixed">
+           <horstretch>0</horstretch>
+           <verstretch>0</verstretch>
+          </sizepolicy>
+         </property>
+         <property name="toolTip">
+          <string>Select a translation function to use</string>
+         </property>
+         <property name="sizeAdjustPolicy">
+          <enum>QComboBox::AdjustToMinimumContentsLength</enum>
+         </property>
+        </widget>
+       </item>
+      </layout>
      </item>
      <item>
       <widget class="QLabel" name="info">

glue/dialogs/link_editor/qt/tests/test_link_equation.py

@@ -105,11 +105,11 @@ def test_select_function_helper(self):
         assert self.widget.function is member
 
     def test_select_invalid_function(self):
-        with pytest.raises(KeyError) as exc:
+        with pytest.raises(ValueError) as exc:
             def bad(x):
                 pass
             self.widget.function = (bad, None, None)
-        assert exc.value.args[0].startswith('No function or helper found')
+        assert exc.value.args[0].startswith('Cannot find data')
 
     def test_make_link_function(self):
         widget = LinkEquation()