This function can be called while processing the Windows mouse-button-down message WM_LBUTTONDOWN, for a magnify window's parent window.
Declaration:
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AT_ERRCOUNT ACCUAPI IG_GUI_magnify_track_mouse (
HIGEAR hIGear,
DWORD dwGrpID,
HWND hWndMagnify,
INT nX,
INT nY
);
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Arguments:
| Name | Type | Description |
| hIGear | HIGEAR | HIGEAR handle of image. |
| DwGrpID | DWORD | Identifier of group which is used for drawing the image in the parent window. |
| HwndMagnify | HWND | Handle of GUI Magnify window. |
| nX | INT | X position of left mouse button click. |
| nY | INT | Y position of left mouse button click. |
Return Value:
Returns the number of ImageGear errors that occurred during this function call.
Supported Raster Image Formats:
All pixel formats supported by ImageGear Professional.
Sample:
Magnify, Display, GUI Windows
Example:
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HIGEAR hIGear; /* Global handle of image in parent window */ HWND hWndParent; /* Global Windows handle of that window */ HWND hWndMagnify; /* Global HIGEAR handle of Magnify window */ AT_ERRCOUNT nErrcount; /* Returned count of errors */ ... /* Create a Magnify window for the image in window hWndParent: */ nErrcount = IG_GUI_magnify_window_create ( hIGear, IG_GRP_DEFAULT, hWndParent, "I.G. Mag Window", 50, 50, 200, 200, &hWndMagnify ); ... /* Message-Handling routine: */ LPARAM CALLBACK MsgHandler (HWND hWnd, UINT msg, WPARAM wParam, LPARAM lParam ); { ... switch (msg) { case WM_LBUTTONDOWN: /* if occurred in the Magnify window: */ IG_GUI_magnify_track_mouse ( hIGear, IG_GRP_DEFAULT, hWndMagnify, LOWORD(lParam), HIWORD(lParam) ); /* The above will display magnified, the location where the mouse was just clicked in the parent image window. */ ... } ... } /* See also sample application MAGNIFY. */ |
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Remarks:
This function will show, magnified in the magnify window, the portion of the image that is at the location of the mouse click in the parent window.
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See the function IG_GUI_magnify_window_create(). |
You can obtain the coordinates (nX, nY) of the mouse click, from the parameters passed by Windows with the WM_... message. See the sample application MAGNIFY for a description of how to use this and related IG_GUI_magnify_...() functions.
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You cannot use IG_GUI_..._track_mouse() with a WM_RBUTTONDOWN message. ImageGear only responds to left mouse button clicks. |