134 lines
3.5 KiB
C++

/******************************************************************************
* Copyright (c) 2018(-2023) STMicroelectronics.
* All rights reserved.
*
* This file is part of the TouchGFX 4.21.2 distribution.
*
* This software is licensed under terms that can be found in the LICENSE file in
* the root directory of this software component.
* If no LICENSE file comes with this software, it is provided AS-IS.
*
*******************************************************************************/
/**
* @file touchgfx/widgets/Image.hpp
*
* Declares the touchgfx::Image class.
*/
#ifndef TOUCHGFX_IMAGE_HPP
#define TOUCHGFX_IMAGE_HPP
#include <touchgfx/Bitmap.hpp>
#include <touchgfx/hal/Types.hpp>
#include <touchgfx/widgets/Widget.hpp>
namespace touchgfx
{
/**
* Simple widget capable of showing a bitmap on the display. The bitmap can be alpha-blended
* with the background (or whichever other Drawable might be "underneath" the Image).
* The bitmap can and have areas of varying opacity.
*
* The conversion from image.bmp or image.png to a bitmap that can be used in TouchGFX
* is handled by the Image Converter as part of compiling the project. Each image is
* assigned a unique BITMAP identifier which.
*
* @see Bitmap
*/
class Image : public Widget
{
public:
/**
* Constructs a new Image with a default alpha value of 255 (solid) and a default Bitmap
* (undefined) if none is specified. If a Bitmap is passed to the constructor, the width and
* height of this widget is set to those of the bitmap.
*
* @param bmp (Optional) The bitmap to display.
*
* @see setBitmap
*/
Image(const Bitmap& bmp = Bitmap())
: Widget(), bitmap(bmp), alpha(255)
{
Image::setBitmap(bmp);
}
/**
* Sets the bitmap for this Image and updates the width and height of this widget to match those
* of the Bitmap.
*
* @param bmp The bitmap instance.
*
* @note The user code must call invalidate() in order to update the image on the display.
*/
virtual void setBitmap(const Bitmap& bmp);
/**
* Sets the opacity (alpha value). This can be used to fade it away by gradually
* decreasing the alpha value from 255 (solid) to 0 (invisible).
*
* @param newAlpha The new alpha value. 255=solid, 0=invisible.
*
* @see getAlpha
*
* @note The user code must call invalidate() in order to update the display.
*/
void setAlpha(uint8_t newAlpha)
{
alpha = newAlpha;
}
virtual void draw(const Rect& invalidatedArea) const;
/**
* Gets the Bitmap currently assigned to the Image widget.
*
* @return The current Bitmap of the widget.
*/
Bitmap getBitmap() const
{
return bitmap;
}
/**
* Gets the BitmapId currently assigned to the Image widget.
*
* @return The current BitmapId of the widget.
*/
BitmapId getBitmapId() const
{
return bitmap.getId();
}
/**
* Gets the current alpha value of the widget. The alpha value is in range 255
* (solid) to 0 (invisible).
*
* @return The current alpha value.
*
* @see setAlpha
*/
uint8_t getAlpha() const
{
return alpha;
}
virtual Rect getSolidRect() const;
virtual void invalidateContent() const
{
if (alpha > 0)
{
Widget::invalidateContent();
}
}
protected:
Bitmap bitmap; ///< The Bitmap to display.
uint8_t alpha; ///< The Alpha for this image.
};
} // namespace touchgfx
#endif // TOUCHGFX_IMAGE_HPP