First of all thank you for reading these guide before contributing!
In this guide you can read how can you help in developing the Littlev Graphic Library. These are not strict rules rather just suggestions. If you have a constructive idea just create pull request on this document!
In this guide you can read how can you help in developing the Littlev Graphic Library. If you have a constructive idea just create pull request on this document!
### Table Of Content
*[Who can contribute?](#who-can-contribute)
...
...
@@ -11,19 +11,17 @@ In this guide you can read how can you help in developing the Littlev Graphic Li
*[How to suggest a feature?](#how-to-suggest-a-feature)
*[How to implement a feature?](#how-to-implement-a-feature)
*[Styling guide](#styling-guide)
*[Git Commit Messages](#Git-commit-messages)
*[File format](#file-format)
*[Functions](#functions)
*[Variables](#variables)
*[Defines](#defines)
*[Typedefs](#typedefs)
*[Comments](#comments)
*[Formatting](#formatting)
## Who can contribute?
Everybody is welcome in contributing independently from skills, programming level or any personal attribute.
There are several ways to contribute in the graphics library like:
As graphical interfaces for embedded systems has an increasing relevance today. You also might find important to work with a good graphics library. Now - independently from skills, programming level or any personal attributes - you can influence the development of the graphics library with:
* Report an issue
* Suggest feature
* Fix an issue
...
...
@@ -31,11 +29,9 @@ There are several ways to contribute in the graphics library like:
Please, take a look at [CODE_OF_CONDUCT](https://github.com/littlevgl/lvgl/blob/master/docs/CODE_OF_CONDUCT.md)
Continue reading to know how you can be part of the development! We are waiting for you!
## How to report an issue?
There are 3 permanent branches:
*`master` for stable, released versions
*`beta` for developers, all feature branches merged here first
*`bugfix` for hotfixes, not new features
### Simple issue
If you find an issue which is very simple to fix, and you fixed it, please send a pull request against `beta` branch.
...
...
@@ -72,21 +68,15 @@ If you have a good and useful idea you can use GitHub issues to suggest a new fe
After a discussion we figure out the specification of the new feature and the technical details/implementation possibilities.
With the knowledge of how to do it somebody can implement the new feature.
The new feature should be in a new branch.
Keep in mind if you wouldn't like to do the implementation there is no guarantee that it will be ready in the new future.
However if you would like to force it, take a look at this page: [Feature request service](http://www.gl.littlev.hu/services#feature)
## How to implement a feature?
In [docs/TODO_MINOR.md](https://github.com/littlevgl/lvgl/blob/master/docs/TODO_MINOR.md) and [docs/TODO_PATCH.md](https://github.com/littlevgl/lvgl/blob/master/docs/TODO_PATCH.md) you can see some ideas which are waiting for somebody to realize them! If want to deal with a feature from this files, please start an issue and discusse the details.
## Styling guide
The new feature should be in a new branch.
### Git Commit Messages
* Use the present tense ("Add feature" not "Added feature")
* Use the imperative mood ("Move cursor to..." not "Moves cursor to...")
* Limit the first line to 72 characters or less
* Reference issues and pull requests liberally after the first line
## Styling guide
### File format
Use [misc/templ/templ.c](https://github.com/littlevgl/misc/blob/master/templ/templ.c) and [misc/templ/templ.h](https://github.com/littlevgl/misc/blob/master/templ/templ.h)
...
...
@@ -114,23 +104,32 @@ Names can be used freely.
### Variables
* words sparated by '_'
* always lower case
* one line one declaration (BAD: char x, y;)
* one line, one declaration (BAD: char x, y;)
* use `<stdint.h>` (*uint8_t*, *int32_t* etc)
* declare variables when needed (not all at function start)
* use the smallest required scope
* variables in a file (outside functions) are always *static*
* do not use global variables (use functions to set/get static variables)
### Defines
### Defines
* always upper case
* starts with *LV_*
* followed by the modul: *OBJ*, *BTN* etc.
* closed by the subject: *ANIM_TIME*, *VALUE_MIN*, *WIDTH_DEF*
### Typedefs
- prefer `typedef struct` instead of `struct name`
- prefer `typedef enum` instead of `enum name`
- types always lowercase speperated by '_'
- first word for public typedefs is *lv_...*
- next word identifies the modul: *lv_obj_...*, *lv_btn_...*
- always add closing *..._t*
- Examples: *lv_obj_t*, *lv_cont_layout_t*
### Comments
Before every function have a comment like this:
```
```c
/**
* Return with the screen of an object
* @param obj pointer to an object
...
...
@@ -150,7 +149,7 @@ You should write **why** have you done this:
### Formatting
Here is example to show bracket placing and using of white spaces:
```
```c
/**
* Set a new text for a label. Memory will be allocated to store the text by the label.
LittlevGL is a graphics library to create Graphical User Interfaces (GUI) on TFT, LCD or monochrome displays using microcontroller based embedded systems.
LittlevGL is a graphics library to create Graphical User Interfaces (GUI) on TFT, LCD or monochrome displays for microcontroller based embedded systems.
Transparency, anti-aliassing and smooth animations can be used with no double buffering so typically no external memories are required.
Transparency, anti-aliassing and smooth animations can be used with no double buffering so typically no external memories are required. Layouts, scrolling, word-wrapping, layers and other features make your job easier.
The graphics library is written in C and it is completely hardware independent. You can even run it in a PC simulator without any embedded hardware.
@@ -8,18 +8,21 @@ Please create an issue to suggest a new feature instead of adding pull request t
Here are ideas which are not assigned to a minor version yet:
- label: add a horzintal line (e.g. underline or line through).
- label long mode: dot begin
- music player app
- files app update: show content as text
- GUI remote control
- automatically build GUI from file (e.g. XML, JSON or HTML)
- lv_split: new object type, a hor. or ver. line for decoration purpose
- lv_valset: new object type, a label with "+" and "-" buttons
- lv_tabview: new object type to organise content with tabs
- lv_btngrp: new object type to display more buttons to choose an option from them
- lv_switch: new object type, turn on/off by tap (a little slider)
- lv_roller: new object type, a roller to select a value (like on smartphones)
## v4.2
## v4.3 (in progress)
-[x] UTF-8 support
-[] lv_split: new object type, a hor. or ver. line for decoration purpose
-[] lv_valset: new object type, a label with "+" and "-" buttons
-[] lv_tabview: new object type to organise content with tabs
-[x] lv_sw: new object type, switch, turn on/off by tap (a little slider)
-[] lv_roller: new object type, a roller to select a value (like on smartphones)
-[x] lv_kb: new object type, Keyboard
-[x] lv_btnm: lv_btnm_set_tgl() to toggle last button
-[x] lv_ta: cursor types
## v4.2 (released at: 17.08.2017)
-[x] Double VDB support: one for rendering, another to transfer former rendered image to frame buffer in the background (e.g. with DMA) [#15](https://github.com/littlevgl/lvgl/issues/15)
-[x] lv_group: to control without touch pad. Issue [#14](https://github.com/littlevgl/lvgl/issues/14)
-[x] lv_page: scrl def fit modification: hor:false, ver:true, and always set width to parent width
