概述

在实际项目中，经常需要用到独立按键来作为人机交互的工具。为了避免重复造轮子，这里简单介绍一个使用组件FlexibleButton的移植，它支持单击、双击、长按等常用事件。

正文

废话不多说，直接开盘。

第一步：获取源码

链接

第二步：准备好工程，并把源文件加入工程。

第三步：注册按键

参考代码如下：

static flex_button_t user_button[1];

static void flex_key_init(void)
{
	GPIO_InitTypeDef GPIO_InitStructure;

	RCC_APB2PeriphClockCmd(RCC_APB2Periph_GPIOA, ENABLE);

	GPIO_InitStructure.GPIO_Speed = GPIO_Speed_50MHz;

	GPIO_InitStructure.GPIO_Mode = GPIO_Mode_IPD;
	GPIO_InitStructure.GPIO_Pin = GPIO_Pin_0;
	GPIO_Init(GPIOA, &GPIO_InitStructure);
}

static uint8_t button_key0_read(void)
{
    return GPIO_ReadInputDataBit(GPIOA, GPIO_Pin_0);
}

static void btn_0_cb(flex_button_t *btn)
{
	char_device_t *uart_dev = NULL;
	uart_dev = char_device_find("uart");
	switch (btn->event)
	{
		case FLEX_BTN_PRESS_DOWN:
			uart_dev->dops->write("key down\r\n", 10);
		break;

		case FLEX_BTN_PRESS_CLICK:
			uart_dev->dops->write("key click\r\n", 11);
		break;

		case FLEX_BTN_PRESS_DOUBLE_CLICK:
			uart_dev->dops->write("key dclick\r\n", 12);
		break;

		case FLEX_BTN_PRESS_SHORT_START:
			uart_dev->dops->write("key short\r\n", 11);
		break;

		case FLEX_BTN_PRESS_SHORT_UP:
			uart_dev->dops->write("key shortup\r\n", 13);
		break;

		case FLEX_BTN_PRESS_LONG_START:
			uart_dev->dops->write("key long\r\n", 10);
		break;

		case FLEX_BTN_PRESS_LONG_UP:
			uart_dev->dops->write("key longup\r\n", 12);
		break;

		case FLEX_BTN_PRESS_LONG_HOLD:
			uart_dev->dops->write("key longhold\r\n", 14);
		break;

		case FLEX_BTN_PRESS_LONG_HOLD_UP:
			uart_dev->dops->write("key longholdup\r\n", 16);
		break;

		case FLEX_BTN_PRESS_REPEAT:
			uart_dev->dops->write("key repeat\r\n", 12);
		break;
	}
}

static void flex_key_struct_init(void)
{
	flex_key_init();
	rt_memset(&user_button[0], 0x0, sizeof(user_button));

	user_button[0].usr_button_read = button_key0_read;
    user_button[0].cb = (flex_button_response_callback)btn_0_cb;
    
    user_button[0].status = 0;
    user_button[0].pressed_logic_level = 1;
    user_button[0].click_start_tick = 20;
    user_button[0].short_press_start_tick = 100;
    user_button[0].long_press_start_tick = 200;
    user_button[0].long_hold_start_tick = 300;
    user_button[0].repeat_interval_tick = 20;

    flex_button_register(&user_button[0]);
}

void KEYthread_entry(void *para)
{
	flex_key_struct_init();
	while(1)
	{
		flex_button_scan();
		rt_thread_mdelay(10);
	}
}

第四步：修改源码

由于原版源码不支持按键长按连发功能，所以简单修改，以增加按键连发功能。
修改代码如下：

static void flex_button_process(void)
{
	......
	case 5: /* is long pressed */
	   if (!(cont & (1 << i))) /* is up */
       {
           target->status = 2;
       }
       else if (target->scan_cnt >= target->long_hold_start_tick)
       {
           target->status = 6;
           repeat_cnt = 0;
           target->event = FLEX_BTN_PRESS_LONG_HOLD;
           EVENT_CB_EXECUTOR(target);
       }
	 break;

     case 6: /* is long pressed */
         if (!(cont & (1 << i))) /* is up */
         {
             target->status = 2;
         }
         else
         {
			if(++repeat_cnt >= target->repeat_interval_tick)
         	{
         		repeat_cnt = 0;
         		target->event = FLEX_BTN_PRESS_REPEAT;
             	EVENT_CB_EXECUTOR(target);
         	}
         }
         break;
}