matplotlib · tacaswell · Aug 21, 2016 · Aug 1, 2016 · Aug 2, 2016 · Aug 2, 2016
diff --git a/doc/api/api_changes/2016-08-02-toggle-grids.rst b/doc/api/api_changes/2016-08-02-toggle-grids.rst
@@ -0,0 +1,9 @@
+Improved toggling of the axes grids
+-----------------------------------
+The `g` key binding now switches the states of the `x` and `y` grids
+independently (by cycling through all four on/off combinations).
+
+The new `G` key binding switches the states of the minor grids.
+
+Both bindings are disabled if only a subset of the grid lines (in either
+direction) is visible, to avoid making irreversible changes to the figure.
diff --git a/doc/users/navigation_toolbar.rst b/doc/users/navigation_toolbar.rst
@@ -99,7 +99,8 @@ Close all plots                    **shift** + **w**
 Constrain pan/zoom to x axis       hold **x** when panning/zooming with mouse
 Constrain pan/zoom to y axis       hold **y** when panning/zooming with mouse
 Preserve aspect ratio              hold **CONTROL** when panning/zooming with mouse
-Toggle grid                        **g** when mouse is over an axes
+Toggle major grids                 **g** when mouse is over an axes
+Toggle minor grids                 **G** when mouse is over an axes
 Toggle x axis scale (log/linear)   **L** or **k**  when mouse is over an axes
 Toggle y axis scale (log/linear)   **l** when mouse is over an axes
 ================================== =================================================

diff --git a/lib/matplotlib/backend_bases.py b/lib/matplotlib/backend_bases.py
@@ -2482,9 +2482,10 @@ def key_press_handler(event, canvas, toolbar=None):
     save_keys = rcParams['keymap.save']
     quit_keys = rcParams['keymap.quit']
     grid_keys = rcParams['keymap.grid']
+    grid_minor_keys = rcParams['keymap.grid_minor']
     toggle_yscale_keys = rcParams['keymap.yscale']
     toggle_xscale_keys = rcParams['keymap.xscale']
-    all = rcParams['keymap.all_axes']
+    all_keys = rcParams['keymap.all_axes']
 
     # toggle fullscreen mode (default key 'f')
     if event.key in fullscreen_keys:
@@ -2524,33 +2525,72 @@ def key_press_handler(event, canvas, toolbar=None):
         return
 
     # these bindings require the mouse to be over an axes to trigger
+    def _get_uniform_gridstate(ticks):
+        # Return True/False if all grid lines are on or off, None if they are
+        # not all in the same state.
+        if all(tick.gridOn for tick in ticks):
+            return True
+        elif not any(tick.gridOn for tick in ticks):
+            return False
+        else:
+            return None
 
-    # switching on/off a grid in current axes (default key 'g')
+    ax = event.inaxes
+    # toggle major grids in current axes (default key 'g')
+    # Both here and below (for 'G'), we do nothing is the grids are not in a
+    # uniform state, to avoid messing up user customization.
     if event.key in grid_keys:
-        event.inaxes.grid()
-        canvas.draw()
+        x_state = _get_uniform_gridstate(ax.xaxis.majorTicks)
+        y_state = _get_uniform_gridstate(ax.yaxis.majorTicks)
+        cycle = [(False, False), (True, False), (True, True), (False, True)]
+        try:
+            x_state, y_state = (
+                cycle[(cycle.index((x_state, y_state)) + 1) % len(cycle)])
+        except ValueError:
+            # Exclude major grids not in a uniform state.
+            pass
+        else:
+            ax.grid(x_state, which="major", axis="x")
+            ax.grid(y_state, which="major", axis="y")
+            canvas.draw_idle()
+    # toggle major and minor grids in current axes (default key 'G')
+    if (event.key in grid_minor_keys
+            # Exclude major grids not in a uniform state.
+            and None not in [_get_uniform_gridstate(ax.xaxis.majorTicks),
+                             _get_uniform_gridstate(ax.yaxis.majorTicks)]):
+        x_state = _get_uniform_gridstate(ax.xaxis.minorTicks)
+        y_state = _get_uniform_gridstate(ax.yaxis.minorTicks)
+        cycle = [(False, False), (True, False), (True, True), (False, True)]
+        try:
+            x_state, y_state = (
+                cycle[(cycle.index((x_state, y_state)) + 1) % len(cycle)])
+        except ValueError:
+            # Exclude minor grids not in a uniform state.
+            pass
+        else:
+            ax.grid(x_state, which="both", axis="x")
+            ax.grid(y_state, which="both", axis="y")
+            canvas.draw_idle()
     # toggle scaling of y-axes between 'log and 'linear' (default key 'l')
     elif event.key in toggle_yscale_keys:
-        ax = event.inaxes
         scale = ax.get_yscale()
         if scale == 'log':
             ax.set_yscale('linear')
-            ax.figure.canvas.draw()
+            ax.figure.canvas.draw_idle()
         elif scale == 'linear':
             ax.set_yscale('log')
-            ax.figure.canvas.draw()
+            ax.figure.canvas.draw_idle()
     # toggle scaling of x-axes between 'log and 'linear' (default key 'k')
     elif event.key in toggle_xscale_keys:
-        ax = event.inaxes
         scalex = ax.get_xscale()
         if scalex == 'log':
             ax.set_xscale('linear')
-            ax.figure.canvas.draw()
+            ax.figure.canvas.draw_idle()
         elif scalex == 'linear':
             ax.set_xscale('log')
-            ax.figure.canvas.draw()
+            ax.figure.canvas.draw_idle()
 
-    elif (event.key.isdigit() and event.key != '0') or event.key in all:
+    elif (event.key.isdigit() and event.key != '0') or event.key in all_keys:
         # keys in list 'all' enables all axes (default key 'a'),
         # otherwise if key is a number only enable this particular axes
         # if it was the axes, where the event was raised

diff --git a/lib/matplotlib/backend_tools.py b/lib/matplotlib/backend_tools.py
@@ -399,24 +399,74 @@ def trigger(self, sender, event, data=None):
                 a.set_navigate(i == n)
 
 
-class ToolGrid(ToolToggleBase):
-    """Tool to toggle the grid of the figure"""
+class _ToolGridBase(ToolBase):
+    """Common functionality between ToolGrid and ToolMinorGrid."""
 
-    description = 'Toogle Grid'
-    default_keymap = rcParams['keymap.grid']
+    _cycle = [(False, False), (True, False), (True, True), (False, True)]
 
     def trigger(self, sender, event, data=None):
-        if event.inaxes is None:
+        ax = event.inaxes
+        if ax is None:
             return
-        ToolToggleBase.trigger(self, sender, event, data)
+        try:
+            x_state, y_state, which = self._get_next_grid_states(ax)
+        except ValueError:
+            pass
+        else:
+            ax.grid(x_state, which=which, axis="x")
+            ax.grid(y_state, which=which, axis="y")
+            ax.figure.canvas.draw_idle()
 
-    def enable(self, event):
-        event.inaxes.grid(True)
-        self.figure.canvas.draw_idle()
+    @staticmethod
+    def _get_uniform_grid_state(ticks):
+        """
+        Check whether all grid lines are in the same visibility state.
 
-    def disable(self, event):
-        event.inaxes.grid(False)
-        self.figure.canvas.draw_idle()
+        Returns True/False if all grid lines are on or off, None if they are
+        not all in the same state.
+        """
+        if all(tick.gridOn for tick in ticks):
+            return True
+        elif not any(tick.gridOn for tick in ticks):
+            return False
+        else:
+            return None
+
+
+class ToolGrid(_ToolGridBase):
+    """Tool to toggle the major grids of the figure"""
+
+    description = 'Toogle major grids'
+    default_keymap = rcParams['keymap.grid']
+
+    def _get_next_grid_states(self, ax):
+        x_state, y_state = map(self._get_uniform_grid_state,
+                               [ax.xaxis.majorTicks, ax.yaxis.majorTicks])
+        cycle = self._cycle
+        # Bail out (via ValueError) if major grids are not in a uniform state.
+        x_state, y_state = (
+            cycle[(cycle.index((x_state, y_state)) + 1) % len(cycle)])
+        return x_state, y_state, "major"
+
+
+class ToolMinorGrid(_ToolGridBase):
+    """Tool to toggle the major and minor grids of the figure"""
+
+    description = 'Toogle major and minor grids'
+    default_keymap = rcParams['keymap.grid_minor']
+
+    def _get_next_grid_states(self, ax):
+        if None in map(self._get_uniform_grid_state,
+                       [ax.xaxis.majorTicks, ax.yaxis.majorTicks]):
+            # Bail out if major grids are not in a uniform state.
+            raise ValueError
+        x_state, y_state = map(self._get_uniform_grid_state,
+                               [ax.xaxis.minorTicks, ax.yaxis.minorTicks])
+        cycle = self._cycle
+        # Bail out (via ValueError) if minor grids are not in a uniform state.
+        x_state, y_state = (
+            cycle[(cycle.index((x_state, y_state)) + 1) % len(cycle)])
+        return x_state, y_state, "both"
 
 
 class ToolFullScreen(ToolToggleBase):
@@ -944,6 +994,7 @@ def _mouse_move(self, event):
                  'subplots': 'ToolConfigureSubplots',
                  'save': 'ToolSaveFigure',
                  'grid': ToolGrid,
+                 'grid_minor': ToolMinorGrid,
                  'fullscreen': ToolFullScreen,
                  'quit': ToolQuit,
                  'quit_all': ToolQuitAll,

diff --git a/lib/matplotlib/rcsetup.py b/lib/matplotlib/rcsetup.py
@@ -1313,6 +1313,7 @@ def validate_animation_writer_path(p):
     'keymap.quit':         [['ctrl+w', 'cmd+w', 'q'], validate_stringlist],
     'keymap.quit_all':     [['W', 'cmd+W', 'Q'], validate_stringlist],
     'keymap.grid':         [['g'], validate_stringlist],
+    'keymap.grid_minor':   [['G'], validate_stringlist],
     'keymap.yscale':       [['l'], validate_stringlist],
     'keymap.xscale':       [['k', 'L'], validate_stringlist],
     'keymap.all_axes':     [['a'], validate_stringlist],

diff --git a/matplotlibrc.template b/matplotlibrc.template
@@ -584,7 +584,8 @@ backend      : $TEMPLATE_BACKEND
 #keymap.zoom : o                     # zoom mnemonic
 #keymap.save : s                     # saving current figure
 #keymap.quit : ctrl+w, cmd+w         # close the current figure
-#keymap.grid : g                     # switching on/off a grid in current axes
+#keymap.grid : g                     # switching on/off major grids in current axes
+#keymap.grid_minor : G               # switching on/off minor grids in current axes
 #keymap.yscale : l                   # toggle scaling of y-axes ('log'/'linear')
 #keymap.xscale : L, k                # toggle scaling of x-axes ('log'/'linear')
 #keymap.all_axes : a                 # enable all axes