嵌入式linux之go语言开发（九）关于嵌入式GUI
go语言没有官方的GUI。
其实怎么说呢，这一块儿的需求也不怎么迫切。毕竟每个语言都有自己擅长的领域。
在电脑上开发界面还是C#或QT或java的swing来的快。没必要非用go吧，更多的是在电脑上基于web的BS架构的模式。
在嵌入式上呢？笔者考察了好多GUI，目前没有发现太满意的。
如QT,LittlevGL,Guilite,awtk,Nuklear等。
这些GUI怎么说呢？要么太庞大，要么依赖一大堆，要么环境就要倒弄很久。有的需要花不少精力去投入学习成本。
但是对我们的嵌入式应用来说，界面不多，有的界面很简单啊，不需要花太多精力在界面上面。用这些就显得划不来了。
有最基础的画点，画线，画圆，图片展示就够了。
UCGUI这个GUI，搞嵌入式的基本都知道吧，比较常见，开源，且使用简单。单片机上都能用。
因此，我把UCGUI和汉字字库做了个go语言的封装。
使用起来也很简单。想要啥界面，自己画呗，反正又不多，界面也不花哨。
有人说都自己实现太花时间了吧，比如选用其他的如ZLG的awtk,或者QT,或者littlegl，或者GTK等。但是我要说，不花这时间花那时间，其实最终花的时间都差不多，甚至还没有自己画的来的快。但若界面很复杂花哨，那还是考虑其他GUI吧，自己画太难了。
简单快速的实现功能就是最好。你倒腾那些GUI就不花时间了吗。除非实在是实现不了或得不偿失了，可以考虑。
ucGUI也有诸如BUTTON,窗口之类的界面控件。但是结合我们的使用情况来说，那些几乎是摆设没有用到。
还是用的显示汉字，图片，点，线的功能多。
我对ucGUI的调用，使用go做了个封装。然后使用起来很简单，有多简单？
例如：
func main() {
fmt.Println("Hello Go")
GUI_Init()
GUI_SetBkColor(0x954816)
GUI_Clear()
GUI_SetFont(&C.GUI_FontHZ20x20)
GUI_DispStringAt("PRICE", 60, 156)
GUI_DispStringAt("票价", 60, 120)
name := ""
fmt.Println("over!press any key to continue: ")
fmt.Scanln(&name)
}封装ucGUI的过程如下：
package drivers
/*
#cgo CFLAGS: -Iinclude/header
#cgo LDFLAGS: -Llib -lucgui -lm
#include
#include "GUI.h"
//extern const GUI_FONT GUI_FontHZ12;
extern const GUI_FONT GUI_FontHZ20x20;
extern const GUI_FONT GUI_FontHZ32x32;
extern const GUI_FONT GUI_FontHZ76x76;
extern void GUIcache2fb(void);
extern int setGUIcache(unsigned char sta);
extern unsigned char getGUIcache(void);
*/
import "C"
import "unsafe"
import (
"github.com/axgle/mahonia"
)
var (
//GUI_FontHZ12 C.GUI_FONT
GUI_FontHZ20x20 *C.GUI_FONT
GUI_FontHZ32x32 *C.GUI_FONT
GUI_FontHZ76x76 *C.GUI_FONT
GUI_FONT_8_ASCII *C.GUI_FONT
GUI_FONT_8_1 *C.GUI_FONT
GUI_FONT_10S_ASCII *C.GUI_FONT
GUI_FONT_10S_1 *C.GUI_FONT
GUI_FONT_10_ASCII *C.GUI_FONT
GUI_FONT_10_1 *C.GUI_FONT
GUI_FONT_13_ASCII *C.GUI_FONT
GUI_FONT_13_1 *C.GUI_FONT
GUI_FONT_13B_ASCII *C.GUI_FONT
GUI_FONT_13B_1 *C.GUI_FONT
GUI_FONT_13H_ASCII *C.GUI_FONT
GUI_FONT_13H_1 *C.GUI_FONT
GUI_FONT_13HB_ASCII *C.GUI_FONT
GUI_FONT_13HB_1 *C.GUI_FONT
GUI_FONT_16_ASCII *C.GUI_FONT
GUI_FONT_16_1 *C.GUI_FONT
GUI_FONT_16_HK *C.GUI_FONT
GUI_FONT_16_1HK *C.GUI_FONT
GUI_FONT_16B_ASCII *C.GUI_FONT
GUI_FONT_16B_1 *C.GUI_FONT
// GUI_FONT_20_ASCII *C.GUI_FONT
// GUI_FONT_20_1 *C.GUI_FONT
// GUI_FONT_20B_ASCII *C.GUI_FONT
// GUI_FONT_20B_1 *C.GUI_FONT
GUI_FONT_24_ASCII *C.GUI_FONT
GUI_FONT_24_1 *C.GUI_FONT
GUI_FONT_24B_ASCII *C.GUI_FONT
GUI_FONT_24B_1 *C.GUI_FONT
GUI_FONT_32_ASCII *C.GUI_FONT
GUI_FONT_32_1 *C.GUI_FONT
GUI_FONT_32B_ASCII *C.GUI_FONT
GUI_FONT_32B_1 *C.GUI_FONT
GUI_FontD48 *C.GUI_FONT
Rect C.GUI_RECT
)
const (
//================
GUI_TEXTMODE_NORMAL C.int = C.GUI_TEXTMODE_NORMAL
GUI_TEXTMODE_XOR C.int = C.GUI_TEXTMODE_XOR
GUI_TEXTMODE_TRANS C.int = C.GUI_TEXTMODE_TRANS
GUI_TEXTMODE_REV C.int = C.GUI_TEXTMODE_REV
GUI_TM_NORMAL C.int = C.GUI_TM_NORMAL
GUI_TM_XOR C.int = C.GUI_TM_XOR
GUI_TM_TRANS C.int = C.GUI_TM_TRANS
GUI_TM_REV C.int = C.GUI_TM_REV
//===================
/* Text alignment flags, horizontal */
GUI_TA_HORIZONTAL C.int = C.GUI_TA_HORIZONTAL
GUI_TA_LEFT C.int = C.GUI_TA_LEFT
GUI_TA_RIGHT C.int = C.GUI_TA_RIGHT
GUI_TA_CENTER C.int = C.GUI_TA_CENTER
GUI_TA_HCENTER C.int = C.GUI_TA_CENTER /* easier to remember :-) */
/* Text alignment flags, vertical */
GUI_TA_VERTICAL C.int = C.GUI_TA_VERTICAL
GUI_TA_TOP C.int = C.GUI_TA_TOP
GUI_TA_BOTTOM C.int = C.GUI_TA_BOTTOM
GUI_TA_BASELINE C.int = C.GUI_TA_BASELINE
GUI_TA_VCENTER C.int = C.GUI_TA_VCENTER
//===================
GUI_BLUE C.uint = C.GUI_BLUE
GUI_GREEN C.uint = C.GUI_GREEN
GUI_RED C.uint = C.GUI_RED
GUI_CYAN C.uint = C.GUI_CYAN
GUI_MAGENTA C.uint = C.GUI_MAGENTA
GUI_YELLOW C.uint = C.GUI_YELLOW
GUI_LIGHTBLUE C.uint = C.GUI_LIGHTBLUE
GUI_LIGHTGREEN C.uint = C.GUI_LIGHTGREEN
GUI_LIGHTRED C.uint = C.GUI_LIGHTRED
GUI_LIGHTCYAN C.uint = C.GUI_LIGHTCYAN
GUI_LIGHTMAGENTA C.uint = C.GUI_LIGHTMAGENTA
GUI_LIGHTYELLOW C.uint = C.GUI_LIGHTYELLOW
GUI_DARKBLUE C.uint = C.GUI_DARKBLUE
GUI_DARKGREEN C.uint = C.GUI_DARKGREEN
GUI_DARKRED C.uint = C.GUI_DARKRED
GUI_DARKCYAN C.uint = C.GUI_DARKCYAN
GUI_DARKMAGENTA C.uint = C.GUI_DARKMAGENTA
GUI_DARKYELLOW C.uint = C.GUI_DARKYELLOW
GUI_WHITE C.uint = C.GUI_WHITE
GUI_LIGHTGRAY C.uint = C.GUI_LIGHTGRAY
GUI_GRAY C.uint = C.GUI_GRAY
GUI_DARKGRAY C.uint = C.GUI_DARKGRAY
GUI_BLACK C.uint = C.GUI_BLACK
GUI_BROWN C.uint = C.GUI_BROWN
GUI_ORANGE C.uint = C.GUI_ORANGE
GUI_TRANSPARENT C.uint = C.GUI_TRANSPARENT
TOP_BAR_COLOR C.uint = 0x501f08
GUI_IdleColor C.uint = 0x954816
)
func init() {
//GUI_FontHZ12 = C.GUI_FontHZ12
GUI_FontHZ20x20 = &C.GUI_FontHZ20x20
GUI_FontHZ32x32 = &C.GUI_FontHZ32x32
GUI_FontHZ76x76 = &C.GUI_FontHZ76x76
GUI_FONT_8_1 = &C.GUI_Font8_1
GUI_FONT_10S_ASCII = &C.GUI_Font10S_ASCII
GUI_FONT_10S_1 = &C.GUI_Font10S_1
GUI_FONT_10_ASCII = &C.GUI_Font10_ASCII
GUI_FONT_10_1 = &C.GUI_Font10_1
GUI_FONT_13_ASCII = &C.GUI_Font13_ASCII
GUI_FONT_13_1 = &C.GUI_Font13_1
GUI_FONT_13B_ASCII = &C.GUI_Font13B_ASCII
GUI_FONT_13B_1 = &C.GUI_Font13B_1
GUI_FONT_13H_ASCII = &C.GUI_Font13H_ASCII
GUI_FONT_13H_1 = &C.GUI_Font13H_1
GUI_FONT_13HB_ASCII = &C.GUI_Font13HB_ASCII
GUI_FONT_13HB_1 = &C.GUI_Font13HB_1
GUI_FONT_16_ASCII = &C.GUI_Font16_ASCII
GUI_FONT_16_1 = &C.GUI_Font16_1
GUI_FONT_16_HK = &C.GUI_Font16_HK
GUI_FONT_16_1HK = &C.GUI_Font16_1HK
GUI_FONT_16B_ASCII = &C.GUI_Font16B_ASCII
GUI_FONT_16B_1 = &C.GUI_Font16B_1
//GUI_FONT_20_ASCII = &C.GUI_Font20_ASCII
//GUI_FONT_20_1 = &C.GUI_Font20_1
//GUI_FONT_20B_ASCII = &C.GUI_Font20B_ASCII
//GUI_FONT_20B_1 = &C.GUI_Font20B_1
GUI_FONT_24_ASCII = &C.GUI_Font24_ASCII
GUI_FONT_24_1 = &C.GUI_Font24_1
GUI_FONT_24B_ASCII = &C.GUI_Font24B_ASCII
GUI_FONT_24B_1 = &C.GUI_Font24B_1
GUI_FONT_32_ASCII = &C.GUI_Font32_ASCII
GUI_FONT_32_1 = &C.GUI_Font32_1
GUI_FONT_32B_ASCII = &C.GUI_Font32B_ASCII
GUI_FONT_32B_1 = &C.GUI_Font32B_1
GUI_FontD48 = &C.GUI_FontD48
}
func GUI_Init() {
C.GUI_Init()
}
func GUI_Clear() {
C.GUI_Clear()
}
func GUI_SetColor(val C.uint) {
C.GUI_SetColor(C.ulong(val))
}
func GUI_SetBkColor(val C.uint) {
C.GUI_SetBkColor(C.ulong(val))
}
func GUI_SetFont(val *C.struct_GUI_FONT) {
C.GUI_SetFont(val)
}
//注：go中的编码为utf-8,GUI显示汉字使用的GB2312
func GUI_DispStringAt(str string, x, y int) {
enc := mahonia.NewEncoder("gbk")
gbk := enc.ConvertString(str)
cs := C.CString(gbk)
defer C.free(unsafe.Pointer(cs))
C.GUI_DispStringAt(cs, C.int(x), C.int(y))
}
func GUI_DispStringHCenterAt(str string, x, y int) {
enc := mahonia.NewEncoder("gbk")
gbk := enc.ConvertString(str)
cs := C.CString(gbk)
defer C.free(unsafe.Pointer(cs))
C.GUI_DispStringHCenterAt(cs, C.int(x), C.int(y))
}
func GUI_FillRect(x0, y0, x1, y1 int) {
C.GUI_FillRect(C.int(x0), C.int(y0), C.int(x1), C.int(y1))
}
func SetRectAera(x0, y0, x1, y1 int) C.GUI_RECT {
var rClient C.GUI_RECT
rClient.x0 = C.short(x0)
rClient.y0 = C.short(y0)
rClient.x1 = C.short(x1)
rClient.y1 = C.short(y1)
return rClient
}
func GUI_DispStringInRect(str string, rect *C.GUI_RECT, align C.int) {
enc := mahonia.NewEncoder("gbk")
gbk := enc.ConvertString(str)
cs := C.CString(gbk)
defer C.free(unsafe.Pointer(cs))
C.GUI_DispStringInRect(cs, rect, align)
}
func GUI_SetTextMode(mode C.int) {
C.GUI_SetTextMode(mode)
}
func GUIcache2fb() {
C.GUIcache2fb()
}
func SetGUIcache(sta int) {
C.setGUIcache(C.uchar(sta))
}
func GetGUIcache() int {
return int(C.getGUIcache())
}
/*
func main() {
fmt.Println("Hello Go")
GUI_Init()
GUI_SetBkColor(0x954816)
GUI_Clear()
GUI_SetFont(&C.GUI_FontHZ20x20)
GUI_DispStringAt("PRICE", 60, 156)
GUI_DispStringAt("票价", 60, 120)
name := ""
fmt.Println("over!press any key to continue: ")
fmt.Scanln(&name)
}
*/
最后再说下，如何使用呢？其他人要用的话，肯定跑不起来，因为根本找不到ucgui.so这个库文件。
那么这个库文件哪来的呢？
根据自己的平台和需求，交叉编译ucgui的源码吧，编译为ucgui.so。缺少的字库也自己打包进去即可。