BmpBox.h

#pragma once
 
#include "StaticControl.h"
 
namespace sw
{
    enum class BmpBoxSizeMode {
        Normal,       // 位图置于BmpBox左上角
        StretchImage, // 拉伸位图填充BmpBox
        AutoSize,     // 调整BmpBox大小，使其等于所包含位图的大小
        CenterImage,  // 将位图居中显示
        Zoom,         // 图像按照原来的比例缩放
    };
 
    class BmpBox : public StaticControl
    {
    private:
        HBITMAP _hBitmap{NULL};
 
        SIZE _bmpSize{0, 0};
 
        BmpBoxSizeMode _sizeMode{BmpBoxSizeMode::Normal};
 
    public:
        const ReadOnlyProperty<HBITMAP> BmpHandle;
 
        const Property<BmpBoxSizeMode> SizeMode;
 
    public:
        BmpBox();
 
        ~BmpBox();
 
        HBITMAP Load(HBITMAP hBitmap);
 
        HBITMAP Load(HINSTANCE hInstance, int resourceId);
 
        HBITMAP Load(const std::wstring &fileName);
 
        void Clear();
 
        void SizeToImage();
 
    protected:
        virtual bool OnDestroy() override;
 
        virtual bool OnPaint() override;
 
        virtual bool OnSize(const Size &newClientSize) override;
 
        virtual bool OnEraseBackground(HDC hdc, LRESULT &result) override;
 
        virtual Size MeasureOverride(const Size &availableSize) override;
 
    private:
        void _UpdateBmpSize();
 
        void _SetBmp(HBITMAP hBitmap);
 
        HBITMAP _SetBmpIfNotNull(HBITMAP hBitmap);
    };
}