组件开发

实现一个点击切换进度的电量指示灯。

步骤如下所示：

• 创建自定义组件类

创建testLight.cpp和testLight.h文件

• 组件类需继承于tpChildWidget

#ifndef __TEST_LIGHT_H
#define __TEST_LIGHT_H

#include "tpChildWidget.h"
#include "tpEvent.h"

class testLight : public tpChildWidget
{
public:
    testLight(tpChildWidget *parent);

    virtual ~testLight();
};

#endif

• 定义电量最大格数和当前显示格数变量

int maxCount_;
int count_;

• 重写onPaintEvent事件，根据电量格数绘制效果

  • 获取绘制画笔

  tpCanvas* painter = event->canvas();

  • 绘制底色

  painter->box(0, 0, width(), height(), _RGB(255, 255, 255));

  • 根据最大格数计算每个格子的宽度

  int spacing = 3;
  int singleWidth = (width() - (maxCount_ + 1) * spacing) / maxCount_;

  • 根据当前电量绘制电量格子

  for (int i = 0; i < count_; ++i)
  {
      int drawX = spacing + i * (singleWidth + spacing);
      painter->box(drawX, spacing, drawX + singleWidth, height() - spacing, _RGB(128, 255, 128));
  }

• 重写onMouseKeyEvent捕获鼠标点击事件，获取鼠标点击状态

if (event->button() == BUTTON_LEFT)
{
    if (event->state())
    {
        count_++;
        if (count_ > maxCount_)
            count_ = 0;
    }
}

组件测试

testLight* light = new testLight(this);
testButton_->setSize(200, 50);
testButton_->move(150, 300);

演示效果

完整源码如下

testLight.h

#ifndef __TEST_LIGHT_H
#define __TEST_LIGHT_H

#include "tpChildWidget.h"
#include "tpEvent.h"

class testLight : public tpChildWidget
{
public:
    testLight(tpChildWidget *parent);

    virtual ~testLight();

public:
    virtual bool onMouseKeyEvent(tpMouseKeyEvent *event) override;

    virtual bool onPaintEvent(tpObjectPaintEvent *event) override;

private:
    int maxCount_;
    int count_;
};

#endif

---

testLight.cpp

#include "testLight.h"
#include "tpCanvas.h"

testLight::testLight(tpChildWidget *parent)
    : tpChildWidget(parent), maxCount_(4), count_(0)
{
}

testLight::~testLight()
{
}

bool testLight::onMouseKeyEvent(tpMouseKeyEvent *event)
{
    tpChildWidget::onMouseKeyEvent(event);

    if (event->button() == BUTTON_LEFT)
    {
        if (event->state())
        {
            count_++;
            if (count_ > maxCount_)
                count_ = 0;
        }
    }

    return true;
}

bool testLight::onPaintEvent(tpObjectPaintEvent *event)
{
    tpChildWidget::onPaintEvent(event);

    tpCanvas *painter = event->canvas();

    painter->box(0, 0, width(), height(), _RGB(255, 255, 255));

    int spacing = 3;
    int singleWidth = (width() - (maxCount_ + 1) * spacing) / maxCount_;

    for (int i = 0; i < count_; ++i)
    {
        int drawX = spacing + i * (singleWidth + spacing);
        painter->box(drawX, spacing, drawX + singleWidth, height() - spacing, _RGB(128, 255, 128));
    }

    return true;
}