196 lines
8.4 KiB
Markdown
196 lines
8.4 KiB
Markdown
keybrd Library Developer's Guide
|
|
================================
|
|
This guide if for maintaining and writing new classes for the keybrd library and its extension libraries.
|
|
The most common reason for new classes are:
|
|
* Port classes for micro controller or I/O expanders
|
|
* custom layer schemes for multi-layer keyboards
|
|
* experimental features
|
|
|
|
## Who this guide is for
|
|
This guide is for the maintainers and developers of the keybrd library and it's extensions.
|
|
It is assumed the reader is familiar with C++ language including pointers, objects, classes, static class variables, composition, inheritance, polymorphism, and enum.
|
|
Some classes use bit manipulation.
|
|
|
|
## Class inheritance diagrams
|
|
|
|
Keybrd library class inheritance diagram
|
|
```
|
|
Matrix
|
|
|
|
RowBase
|
|
|
|
|
Row
|
|
|
|
IOExpanderPort
|
|
|
|
_______ RowPort _______
|
|
/ | \
|
|
RowPort_AVR RowPort_MCP23018 RowPort_PCA9655E (one RowPort class for each type of IC)
|
|
|
|
_______ ColPort _______
|
|
/ | \
|
|
ColPort_AVR ColPort_MCP23018 ColPort_PCA9655E (one ColPort class for each type of IC)
|
|
|
|
_____ LED ______
|
|
/ | \
|
|
LED_AVR LED_MCP23018 LED_PCA9655E (one LED class for each type of IC)
|
|
|
|
|
|
LayerStateInterface
|
|
|
|
|
LayerState
|
|
|
|
|
|
Key __
|
|
| \
|
|
| Key_LayeredKeysArray
|
|
|
|
|
Code
|
|
|_____________________
|
|
| \ \
|
|
| Code_LayerLock Code_LayerHold
|
|
|
|
|
|___________________________
|
|
| \ \
|
|
| Code_LayeredScScBase Code_LayeredCodeScBase
|
|
| | |
|
|
| Code_LayeredScSc Code_LayeredCodeSc
|
|
|
|
|
|__________________________________________
|
|
\ \ \ \
|
|
Code_Sc Code_Shift Code_AutoShift Code_LockLED
|
|
/ | \
|
|
Code_ScS Code_ScNS Code_ScNS_00
|
|
|
|
```
|
|
|
|
## Dependency diagrams
|
|
|
|
single-layer dependency diagram with LEDs
|
|
```
|
|
matrix[1..*]
|
|
|
|
|
row[1..*]_____________________________
|
|
| \ \ \
|
|
rowPort[1] rowPin[1] colPort[1] keys[1]
|
|
| |
|
|
colPins[1..*] code[1..*]
|
|
|
|
|
LED[1]
|
|
|
|
```
|
|
|
|
multi-layer dependency diagram with LEDs and I/O Expander
|
|
```
|
|
matrix[1..*]
|
|
| layerStates[1..*]
|
|
row[1..*]_________________________________________/__ | \
|
|
| \ \ \ / \ | \
|
|
rowPort[1] rowPin[1] colPort[1] keys[1] / code_layer[1..*] LED[0..*]
|
|
\ / \ | / /
|
|
\ / colPins[1..*] key[1..*] /
|
|
\ / | /
|
|
\ / code[1..*] /
|
|
\ / ______________________________________/
|
|
IOExpanderPort[0..*]
|
|
|
|
```
|
|
|
|
## Class naming conventions
|
|
Class names start with upper case letter.
|
|
Most derived-class names start with the base class name followed by "_" and a name e.g.
|
|
```
|
|
Code
|
|
|
|
|
Code_LayerLock
|
|
|
|
```
|
|
This convention leads to class names that convey information about the classes inheritance.
|
|
Underscore delineates base class name and sub-class name. Capital letters delineate words.
|
|
|
|
## Layer-class naming conventions
|
|
*Code_Layer* class names are concatenations of "Code_", "Layer" or layer name, and persistence.
|
|
Example persistences are:
|
|
* "Lock" - layer remains active after the layer key is released
|
|
* "Hold" - layer is active for as long as layer key is held down
|
|
|
|
Example Code_Layer class names:
|
|
* Code_LayerHold
|
|
* Code_LayerLock
|
|
|
|
*LayerState* class names start with "LayerState" and end with a descriptive name.
|
|
Example LayerState class names:
|
|
* LayerState - basic LayerState class in keybrd library
|
|
* LayerState_DH - main LayerState for the keybrd_DH library
|
|
* LayerState_MF - LayerState for Mouse Function sub-layers in the keybrd_DH library
|
|
|
|
*Code_Layered* class names start with "Code_Layered" and end with a descriptive name.
|
|
Example Code_Layered class names:
|
|
* Code_LayeredScSc
|
|
* Key_LayeredKeysArray
|
|
|
|
## Style guide
|
|
Following the style guide makes it easier for the next programmer to understand your code.
|
|
* For class names, see above section "Class naming conventions"
|
|
* For member names, use camelCase starting with lowercase letter.
|
|
* Use constants rather than macros, except for header guards.
|
|
* For constant names that could be macros, use ALL_CAPS_AND_UNDERSCORE.
|
|
* **ITEM_COUNT** is a constant number of items.
|
|
* **itemCount** is a variable number of items.
|
|
* Use header guards CLASS_NAME_H.
|
|
* Prefix pointer name with "ptr" e.g. ptrRow = &row;
|
|
* Name arrays using the plural of element name e.g. Row* const = ptrsRows { &row0, &row1 };
|
|
* Pass arrays using array notation rather than pointer notation. Use
|
|
```
|
|
void printArray(char[] array);
|
|
not
|
|
void printArray( char* array);
|
|
```
|
|
* In constructor's initialization list, use same names for fields and constructor parameters.
|
|
* Do not use new or malloc (making memory leaks impossible).
|
|
* If class has any non-[POD](http://en.wikipedia.org/wiki/Plain_old_data_structure) data members, [do not inline constructors and destructors](http://www.chromium.org/developers/coding-style/cpp-dos-and-donts).
|
|
* Document class interface in .h file, above the class declaration.
|
|
* Code should be self-documenting. The only comments should be things that may need clarification. A simple function with a good name needs no comment.
|
|
* Code is automatically formated before being pushed to the keybrd repository.
|
|
The [astyle_cpp](astyle_cpp) file specifies the format:
|
|
* Allman style indentation
|
|
* indent 4 spaces
|
|
* replace tabs with spaces
|
|
* maximum code width of 100 columns
|
|
|
|
<!-- http://stackoverflow.com/questions/2198241/best-practice-for-c-function-commenting -->
|
|
|
|
## Trace of keybrd scan
|
|
Arduino does not have a debugger; so here is a list of functions in the order that they are called.
|
|
Refer to it like a table of contents while reading the keybrd library.
|
|
|
|
```
|
|
Matrix::scan() for each row
|
|
Row::process()
|
|
Row::scan()
|
|
RowPort_*::setActivePin*() strobe row on
|
|
for each col port
|
|
ColPort_*::read() read col port
|
|
RowPort_*::setActivePin*() strobe row off
|
|
Row::getRowState() for each col port
|
|
for each connected col pin
|
|
if key is pressed
|
|
set rowState bit
|
|
Row::debounce() debounce
|
|
Row::detectEdge() detect edge
|
|
Row::pressRelease() for each key in row
|
|
if rising edge
|
|
Key_*::press() scanCode->press()
|
|
Code_*::press() Keyboard.press(scancode)
|
|
```
|
|
|
|
## The Arduino libraries
|
|
The keybrd libraries compile on the Arduino IDE and make extensive use of the following [Arduino libraries](https://www.arduino.cc/en/Reference/Libraries):
|
|
|
|
#include <Arduino.h>
|
|
#include <Wire.h>
|
|
#include <Keyboard.h>
|
|
#include <Mouse.h>
|
|
|
|
<a rel="license" href="http://creativecommons.org/licenses/by/4.0/"><img alt="Creative Commons License" style="border-width:0" src="https://i.creativecommons.org/l/by/4.0/88x31.png" /></a><br /><span xmlns:dct="http://purl.org/dc/terms/" property="dct:title">keybrd guide</span> by <a xmlns:cc="http://creativecommons.org/ns#" href="https://github.com/wolfv6/keybrd" property="cc:attributionName" rel="cc:attributionURL">Wolfram Volpi</a> is licensed under a <a rel="license" href="http://creativecommons.org/licenses/by/4.0/">Creative Commons Attribution 4.0 International License</a>.<br />Permissions beyond the scope of this license may be available at <a xmlns:cc="http://creativecommons.org/ns#" href="https://github.com/wolfv6/keybrd/issues/new" rel="cc:morePermissions">https://github.com/wolfv6/keybrd/issues/new</a>.
|