UI系统

1.数据结构抽象

抽象一个按钮数据结构，包括名称、区域、绘制函数、按压处理函数。

typedef struct Button

{

char *name;

Region tRegion;

int (*OnDraw)(struct Button *PButton, PDispBuff ptDispBuff); //绘制button

int (*OnPressed)(struct Button *PButton, PDispBuff ptDispBuff, PInputEvent ptInputEvent); //按压输入

} Button, *PButton;

定义函数指针后：

#define BUTTON_DEFAULT_COLOR 0xff0000

#define BUTTON_PRESSED_COLOR 0x00ff00

#define BUTTON_TEXT_COLOR 0x000000

/* 定义函数指针 */

typedef int (*ONDRAW_FUNC)(struct Button *PButton, PDispBuff ptDispBuff);

typedef int (*ONPRESSED_FUNC)(struct Button *PButton, PDispBuff ptDispBuff, PInputEvent ptInputEvent);

typedef struct Button

{

char *name;

Region tRegion;

ONDRAW_FUNC OnDraw; //绘制button

ONPRESSED_FUNC OnPressed; //按压输入

} Button, *PButton;

2.按键

创建ui\button.c：编写上面三个函数

• 初始化函数InitButton:初始化按键结构体

  void InitButton(char *name, PButton ptButton, PRegion ptRegion, ONDRAW_FUNC OnDraw,

  ONPRESSED_FUNC OnPressed)

  {

  ptButton->name = name;

  ptButton->status = 0;

  ptButton->tRegion = *ptRegion;

  ptButton->OnDraw = OnDraw ? OnDraw : DefaultOnDraw;

  ptButton->OnPressed = OnPressed ? OnPressed : DefaultOnPressed;

  }

  然后在没有提供绘制和按下处理函数的情况下，我们需要有默认的函数，DefaultOnDraw、 DefaultOnPressed

• 绘制默认状态函数DefaultOnDraw：

  static int DefaultOnDraw(struct Button *ptButton, PDispBuff ptDispBuff)

  {

  // 绘制底色

  DrawRegion(&ptButton->tRegion, BUTTON_DEFAULT_COLOR);

  // 居中文字

  DrawTextInRegionCentrl(ptButton->name, &ptButton->tRegion, BUTTON_TEXT_COLOR);

  // flush to lcd or web

  FlushDispalyRegion(&ptButton->tRegion, ptDispBuff);

  }

  相关函数在display/disp_manager.c中实现：

  • DrawRegion：绘制一个区域ptRegion成一种颜色dwColor

    void DrawRegion(PRegion ptRegion, unsigned int dwColor)

    {

    int x, y, width, heigh;

    int i, j;

    x = ptRegion->iLeftUpX;

    y = ptRegion->iLeftUpy;

    width = ptRegion->iWidth;

    heigh = ptRegion->iHight;

    for (j = y; j < y + heigh; j++)

    {

    for (i = x; i < x + width; i++)

    {

    PutPixel(i, j, dwColor);

    }

    }

    }

  • DrawTextInRegionCentrl ：绘制居中文字

    

    计算文字原点(起笔点)、大小，设置大小，循环获取文字位图，绘制所有文字

    void DrawTextInRegionCentrl(char *name, PRegion ptRegion, unsigned int dwColor)

    {

    int n = strlen(name);

    int iFontSize = ptRegion->iWidth / n / 2;

    int iOriginX, iOriginY;

    int i = 0;

    FontBitMap tFontBitMap;

    if (iFontSize > ptRegion->iHight)

    {

    iFontSize = ptRegion->iHight

    }

    SetFontSize(iFontSize);

    iOriginX = (ptRegion->iWidth - n * iFontSize) / 2 + ptRegion->iLeftUpX;

    iOriginY = (ptRegion->iHight - iFontSize) / 2 + iFontSize + ptRegion->iLeftUpX;

    while (name[i])

    {

    tFontBitMap.iCurOriginX = iOriginX;

    tFontBitMap.iCurOriginY = iOriginY;

    err = GetFontBitMap(name[i], &tFontBitMap);

    if (err)

    {

    printf("%c GetFontBitMap err\n", str[i]);

    return -1;

    }

    /* 绘制位图 */

    DrawFontBitMap(&tFontBitMap, dwColor);

    /* 更新 */

    iOriginX = tFontBitMap.iNextOriginX;

    iOriginY = tFontBitMap.iNextOriginY;

    i++;

    }

    }

  • FlushDispalyRegion：刷新区域到lcd或web，之前已经实现

• DefaultOnPressed：设置按键的状态翻转，修改底色

  static int DefaultOnPressed(struct Button *ptButton, PDispBuff ptDispBuff, PInputEvent ptInputEvent)

  {

  unsigned int dwColor = BUTTON_DEFAULT_COLOR;

  ptButton->status = !ptButton->status;

  if (1 == ptButton->status)

  {

  dwColor = BUTTON_PRESSED_COLOR;

  }

  //绘制底色

  DrawRegion(&ptButton->tRegion, dwColor);

  //居中写文字

  DrawTextInRegionCentrl(ptButton->name, &ptButton->tRegion, BUTTON_TEXT_COLOR);

  // flush to lcd or web

  FlushDispalyRegion(&ptButton->tRegion, ptDispBuff);

  }

3.测试

（1）编译

ui.hstruct Button需要先声明一下：

struct Button;

/* 定义函数指针 */

typedef int (*ONDRAW_FUNC)(struct Button *PButton, PDispBuff ptDispBuff);

typedef int (*ONPRESSED_FUNC)(struct Button *PButton, PDispBuff ptDispBuff, PInputEvent ptInputEvent);

typedef struct Button

{

char *name;

int status;

Region tRegion;

ONDRAW_FUNC OnDraw; //绘制button

ONPRESSED_FUNC OnPressed; //按压输入

} Button, *PButton;

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