Component Development

Implement a battery indicator whose progress toggles on click.

Steps:

• Create a custom component class

Create TestLight.cpp and TestLight.h

• The component must inherit from TpWidget

#ifndef __TEST_LIGHT_H
#define __TEST_LIGHT_H

#include "TpWidget.h"
#include "tpEvent.h"

class TestLight : public TpWidget
{
public:
    TestLight(TpWidget *parent);

    virtual ~TestLight();
};

#endif

• Define variables for maximum bars and current bars

int maxCount_;
int count_;

• Override onPaintEvent and draw based on the number of bars

  • Get the painter

  TpPainter* painter = event->painter();

  • Draw background

  painter->setPen(_RGB(255, 255, 255));
  painter->setBrush(TpBrush(_RGB(255, 255, 255)));
  painter->drawRect(0, 0, width(), height());

  • Compute each bar width based on the maximum

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

  • Draw bars according to current level

  painter->setPen(_RGB(128, 255, 128));
  painter->setBrush(TpBrush(_RGB(128, 255, 128)));
  for (int i = 0; i < count_; ++i)
  {
      int drawX = spacing + i * (singleWidth + spacing);
      painter->drawRect(drawX, spacing, singleWidth, height() - spacing * 2);
  }

• Override onMousePressEvent to capture mouse press and update state

bool TestLight::onMousePressEvent(TpMouseEvent *event)
{
    TpWidget::onMousePressEvent(event);

    count_++;
    if (count_ > maxCount_)
        count_ = 0;

    return true;
}

Component Test

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

Demo

完整源码如下

TestLight.h

#ifndef __TEST_LIGHT_H
#define __TEST_LIGHT_H

#include "TpWidget.h"
#include "tpEvent.h"

class TestLight : public TpWidget
{
public:
    TestLight(TpWidget *parent);

    virtual ~TestLight();

public:
    virtual bool onMousePressEvent(TpMouseEvent *event) override;

    virtual bool onPaintEvent(TpPaintEvent *event) override;

private:
    int maxCount_;
    int count_;
};

#endif

---

TestLight.cpp

#include "TestLight.h"
#include "TpPainter.h"

TestLight::TestLight(TpWidget *parent)
    : TpWidget(parent), maxCount_(4), count_(0)
{
}

TestLight::~TestLight()
{
}

bool TestLight::onMousePressEvent(TpMouseEvent *event)
{
    TpWidget::onMousePressEvent(event);

    count_++;
    if (count_ > maxCount_)
        count_ = 0;

    return true;
}

bool TestLight::onPaintEvent(TpPaintEvent *event)
{
    TpWidget::onPaintEvent(event);

    TpPainter *painter = event->painter();

    painter->setPen(_RGB(255, 255, 255));
    painter->setBrush(TpBrush(_RGB(255, 255, 255)));

    painter->drawRect(0, 0, width(), height());

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

    painter->setPen(_RGB(128, 255, 128));
    painter->setBrush(TpBrush(_RGB(128, 255, 128)));
    for (int i = 0; i < count_; ++i)
    {
        int drawX = spacing + i * (singleWidth + spacing);
        painter->drawRect(drawX, spacing, singleWidth, height() - spacing * 2);
    }

    return true;
}

Copyright

Copyright Ownership:TinyPiXOS

License under:Attribution-ShareAlike 4.0 International (CC-BY-SA-4.0)