improved modm::ButtonGroup docs

src/modm/ui/button.lb

@@ -12,48 +12,7 @@
 
 def init(module):
     module.name = ":ui:button"
-    module.description = """\
-# Debouncing Buttons
-
-The `modm::ButtonGroup` class is able to debounce eight buttons at the same time.
-The buttons have to be low-active. If this isn't the case invert their signal
-before passing it to the `update()` method.
-
-The `update()` method needs to be called periodically for example
-every 10ms. Preferred in a timer interrupt function.
-
-The detection for long or repeated presses works only correctly for
-one key at a time. This constraint only applies to buttons listed in the
-`mask` variable."""r"""
-
-Mode 1:
-
-```
-                 Timeline ---->
-                      __      _________________      __
-getState()       ____/  \____/                 \____/  \____
-isPressed()      ----X-------X----------------------X-------
-isRepeated()     --------------------X--X--X--X-------------
-isReleased()     -------X----------------------X-------X----
-                             |       |__|__|
-                             |_______| \ /
-                                  \    interval
-                                  timeout
-```
-
-Mode 2:
-
-```
-                      __      _________________      __
-getState()       ____/  \____/                 \____/  \____
-isPressedShort() -------X------------------------------X----
-isPressedLong()  --------------------X----------------------
-isReleased()     -------X----------------------X-------X----
-```
-
-This implementation is based on the C functions written
-by Peter Dannegger (see http://www.mikrocontroller.net/topic/48465).
-"""
+    module.description = FileReader("button.md")
 
 def prepare(module, options):
     module.depends(":architecture:atomic")

src/modm/ui/button.md

@@ -0,0 +1,68 @@
+# Debouncing Buttons
+
+The `modm::ButtonGroup` class is able to debounce eight buttons at the same time.
+The buttons have to be low-active. If this isn't the case invert their signal
+before passing it to the `update()` method.
+
+The `update()` method needs to be called periodically for example every 10ms.
+Preferred in a timer interrupt function.
+
+The detection for long or repeated presses works only correctly for one key at a
+time. This constraint only applies to buttons listed in the `mask` variable.
+
+## Mode 1
+```
+                 Timeline ---->
+                      __      _________________      __
+getState()       ____/  \____/                 \____/  \____
+isPressed()      ----X-------X----------------------X-------
+isRepeated()     --------------------X--X--X--X-------------
+isReleased()     -------X----------------------X-------X----
+                             |       |__|__|
+                             |_______| \ /
+                                  \    interval
+                                  timeout
+```
+
+## Mode 2
+```
+                 Timeline ---->
+                      __      _________________      __
+getState()       ____/  \____/                 \____/  \____
+isPressedShort() -------X------------------------------X----
+isPressedLong()  --------------------X----------------------
+isReleased()     -------X----------------------X-------X----
+```
+
+## Naming Buttons
+
+To name buttons, declare an enum with a bitmask for each button:
+
+```cpp
+#include <modm/math/utils/bit_constants.hpp>
+
+enum ButtonIdentifier
+{
+	NONE = 0x00,
+	BUTTON0 = modm::Bit0,
+	BUTTON1 = modm::Bit1,
+	BUTTON2 = modm::Bit2,
+	BUTTON3 = modm::Bit3,
+	BUTTON4 = modm::Bit4,
+	BUTTON5 = modm::Bit5,
+	BUTTON6 = modm::Bit6,
+	BUTTON7 = modm::Bit7,
+	ALL = 0xFF,
+};
+```
+
+Pass a `ButtonIdentifier` to any of `ButtonGroup::is**()` like so
+
+```cpp
+if(buttongroup_instance.isPressed(BUTTON0)) {
+	// Do stuff
+}
+```
+
+This implementation is based on the C functions written by Peter Dannegger
+(see http://www.mikrocontroller.net/topic/48465).

src/modm/ui/button_group.hpp

@@ -21,31 +21,8 @@
 #include <modm/architecture/utils.hpp>
 #include <modm/architecture/interface/atomic_lock.hpp>
 
-#include <modm/math/utils/bit_constants.hpp>
-
 namespace modm
 {
-
-/**
- * Button masks.
- *
- * Provided for convenience only.
- * Normally it is best to define your own meaningful names for the buttons.
- */
-enum ButtonGroupIdentifier
-{
-	NONE = 0x00,
-	BUTTON0 = Bit0,
-	BUTTON1 = Bit1,
-	BUTTON2 = Bit2,
-	BUTTON3 = Bit3,
-	BUTTON4 = Bit4,
-	BUTTON5 = Bit5,
-	BUTTON6 = Bit6,
-	BUTTON7 = Bit7,
-	ALL = 0xFF,
-};
-
 /**
  * @tparam	T	Storage type for Button states. Each button requires one bit.
  *