第三部分第三章 自己动手开发Button控件

#define NCSCTRL_NEWBUTTON    NCSCLASSNAME("newbutton")

/*在这里定义了，两张图片的PBITMAP，和button所处的状态标实*/
#define mNewButtonHeader(clsName) \
mWidgetHeader(clsName)        \
PBITMAP bmp_nor;              \
PBITMAP bmp_up;               \
int status;

#define mNewButtonClassHeader(clsName, parentClass)           \
mWidgetClassHeader(clsName, parentClass)    

#define mNewButtonRendererHeader(clsName, parentClass)  \
mWidgetRendererHeader(clsName, parentClass)

MGNCS_EXPORT extern mNewButtonClass g_stmNewButtonCls;

enum mNewbuttonProp {
        NCSP_NEWBTN_IMAGE_NORMAL = NCSP_WIDGET_MAX + 1,
        NCSP_NEWBTN_IMAGE_DOWN,
        NCSP_NEWBTN_MAX
};

enum mNewButtonNotify {
        NCSN_NEWBTN_PUSHED = NCSP_WIDGET_MAX + 1
};

/*控件中定义的枚举类型，表示button的两个状态*/
enum mNewButtonStatus {
        BTN_NORMAL   = 1,
        BTN_PUSHED
};

/*类mNewButton的构造函数*/
static void mNewButton_construct(mNewButton *self, DWORD param)
{
        Class(mWidget).construct((mWidget*)self, param);
}

/*类mNewButton的onLButtonDow和onLButtonUp函数，其作用是接收鼠标事件，并通知父窗口。*/
static int mNewButton_onLButtonDown (mNewButton* self, int x, int y, DWORD keyFlags)
{
        SetCapture (self->hwnd);
        self->status = BTN_PUSHED;
        InvalidateRect(self->hwnd, NULL, TRUE);
        return 0;
}

static int mNewButton_onLButtonUp (mNewButton* self, int x, int y, DWORD keyFlags)
{
        if (GetCapture() == self->hwnd){
                self->status = BTN_NORMAL;
                InvalidateRect(self->hwnd, NULL, TRUE);
                ReleaseCapture ();
                ncsNotifyParent((mWidget*)self, NCSN_NEWBTN_PUSHED);
        }
}

/*类mNewButton onPaint的处理函数，其作用是根据button的不同状态，显示不同的图片*/
static void mNewButton_onPaint (mNewButton *self, HDC hdc, const PCLIPRGN pinv_clip)
{
        RECT rect;
        GetWindowRect (self->hwnd, &rect);
        switch (self->status){
                case BTN_NORMAL:
                FillBoxWithBitmap (hdc, 0, 0, RECTW(rect), 
                RECTH(rect), self->bmp_nor);
                break;
                case BTN_PUSHED:
                FillBoxWithBitmap (hdc, 0, 0, RECTW(rect), 
                RECTH(rect), self->bmp_up);
                break;
        }
}

/*类mNewButton setProperty的处理函数，其作用是加载图片，并将其显示出来。*/
static BOOL mNewButton_setProperty (mNewButton *self, int id, DWORD value)
{
        char *str;
        if (id > NCSP_NEWBTN_MAX){
                return FALSE;
        }
        str = (char*)value;
        switch (id){
                case NCSP_NEWBTN_IMAGE_NORMAL:
                self->bmp_nor = LoadBitmapFromRes (HDC_SCREEN, str);
                if (self->bmp_nor == NULL){
                        printf ("Cant load %s\n ", str);
                        return 1;
                }
                break;
                
                case NCSP_NEWBTN_IMAGE_DOWN:
                self->bmp_up = LoadBitmapFromRes (HDC_SCREEN, str);
                if (self->bmp_up == NULL){
                        printf ("Cant load %s\n ", str);
                        return 1;
                }
                break;
        }
        InvalidateRect(self->hwnd, NULL, TRUE);
        return Class(mWidget).setProperty((mWidget*)self, id, value);
}

/*类mNewButton 在销毁的时候使用的destroy函数，其作用是释放使用的图片资源*/
static void mNewButton_destroy(mNewButton *self)
{
        ReleaseRes (Str2Key (self->bmp_nor));
        ReleaseRes (Str2Key (self->bmp_up));
}
/*类mNewButton onCreate的处理函数，其作用是将button的status置为BTN_NORMAL*/
static BOOL mNewButton_onCreate (mNewButton *self, LPARAM lParam)
{
        self->status = BTN_NORMAL;
}