Add select all, reset and invert selection to checkbox

docs/examples.rst

@@ -40,6 +40,11 @@ Result on something like:
 
 |inquirer checkbox|
 
+Apart from all the controlls supported by other questions, checkbox supports some more as shown above:
+
+* `Ctrl + A` to select all.
+* `Ctrl + R` to un-select all the choices, even the defaults.
+* `Ctrl + I` to invert/toggle all the choices.
 
 The :code:`choices` list can also be a list of tuples. The first value in each tuple should be the label displayed to the user. The second value in each tuple should be the actual value for that option. This allows you to have the user choose options that are not plain strings in the code.
 
@@ -64,7 +69,7 @@ Result on something like:
 .. |inquirer list| image:: images/inquirer_list.png
   :alt: Example of List Question
 
-.. |inquirer checkbox| image:: images/inquirer_checkbox.png
+.. |inquirer checkbox| image:: images/inquirer_checkbox.gif
   :alt: Example of Checkbox Question
 
 .. |inquirer theme| image:: images/inquirer_theme.gif

src/inquirer/render/console/_checkbox.py

@@ -96,6 +96,12 @@ def process_input(self, pressed):
         elif pressed == key.RIGHT:
             if self.current not in self.selection:
                 self.selection.append(self.current)
+        elif pressed == key.CTRL_A:
+            self.selection = [i for i in range(len(self.question.choices))]
+        elif pressed == key.CTRL_R:
+            self.selection = []
+        elif pressed == key.CTRL_I:
+            self.selection = [i for i in range(len(self.question.choices)) if i not in self.selection]
         elif pressed == key.ENTER:
             result = []
             for x in self.selection:

tests/acceptance/test_checkbox.py

@@ -60,6 +60,23 @@ def test_select_last(self):
         self.sut.send(key.ENTER)
         self.sut.expect(r"{'interests': \['Computers', 'Books', 'History'\]}.*", timeout=1)  # noqa
 
+    def test_select_all_with_ctrl_a(self):
+        self.sut.send(key.CTRL_A)
+        self.sut.send(key.ENTER)
+        self.sut.expect(
+            r"{'interests': \['Computers', 'Books', 'Science', 'Nature', 'Fantasy', 'History'\]}.*", timeout=1
+        )  # noqa
+
+    def test_reset_with_ctrl_r(self):
+        self.sut.send(key.CTRL_R)
+        self.sut.send(key.ENTER)
+        self.sut.expect(r"{'interests': \[\]}.*", timeout=1)  # noqa
+
+    def test_default_invert_selection_with_ctrl_i(self):
+        self.sut.send(key.CTRL_I)
+        self.sut.send(key.ENTER)
+        self.sut.expect(r"{'interests': \['Science', 'Nature', 'Fantasy', 'History'\]}.*", timeout=1)  # noqa
+
 
 @unittest.skipUnless(sys.platform.startswith("lin"), "Linux only")
 class CheckCarouselTest(unittest.TestCase):

tests/integration/console_render/test_checkbox.py

@@ -240,3 +240,87 @@ def test_left_cursor_do_not_select(self):
         result = sut.render(question)
 
         assert result == []
+
+    def test_select_all(self):
+        stdin_array = [key.CTRL_A, key.ENTER]
+        stdin = helper.event_factory(*stdin_array)
+        message = "Foo message"
+        variable = "Bar variable"
+        choices = ["foo", "bar", "bazz"]
+
+        question = questions.Checkbox(variable, message, choices=choices)
+
+        sut = ConsoleRender(event_generator=stdin)
+        result = sut.render(question)
+
+        assert result == choices
+
+    def test_reset_one_selection(self):
+        stdin_array = [key.SPACE, key.CTRL_R, key.ENTER]
+        stdin = helper.event_factory(*stdin_array)
+        message = "Foo message"
+        variable = "Bar variable"
+        choices = ["foo", "bar", "bazz"]
+
+        question = questions.Checkbox(variable, message, choices=choices)
+
+        sut = ConsoleRender(event_generator=stdin)
+        result = sut.render(question)
+
+        assert result == []
+
+    def test_reset_all_selection(self):
+        stdin_array = [key.CTRL_A, key.CTRL_R, key.ENTER]
+        stdin = helper.event_factory(*stdin_array)
+        message = "Foo message"
+        variable = "Bar variable"
+        choices = ["foo", "bar", "bazz"]
+
+        question = questions.Checkbox(variable, message, choices=choices)
+
+        sut = ConsoleRender(event_generator=stdin)
+        result = sut.render(question)
+
+        assert result == []
+
+    def test_invert_one_selection(self):
+        stdin_array = [key.SPACE, key.CTRL_I, key.ENTER]
+        stdin = helper.event_factory(*stdin_array)
+        message = "Foo message"
+        variable = "Bar variable"
+        choices = ["foo", "bar", "bazz"]
+
+        question = questions.Checkbox(variable, message, choices=choices)
+
+        sut = ConsoleRender(event_generator=stdin)
+        result = sut.render(question)
+
+        assert result == ["bar", "bazz"]
+
+    def test_invert_all(self):
+        stdin_array = [key.CTRL_I, key.ENTER]
+        stdin = helper.event_factory(*stdin_array)
+        message = "Foo message"
+        variable = "Bar variable"
+        choices = ["foo", "bar", "bazz"]
+
+        question = questions.Checkbox(variable, message, choices=choices)
+
+        sut = ConsoleRender(event_generator=stdin)
+        result = sut.render(question)
+
+        assert result == choices
+
+    def test_double_invert_all(self):
+        stdin_array = [key.CTRL_I, key.CTRL_I, key.ENTER]
+        stdin = helper.event_factory(*stdin_array)
+        message = "Foo message"
+        variable = "Bar variable"
+        choices = ["foo", "bar", "bazz"]
+
+        question = questions.Checkbox(variable, message, choices=choices)
+
+        sut = ConsoleRender(event_generator=stdin)
+        result = sut.render(question)
+
+        assert result == []