---
name: "ImgChanged"
section: "3tk"
platform: "linux"
package: "tk8.3-doc"
version: "8.3.5-14"
release: "Debian 5.0 (Lenny)"
platforms: ["linux"]
url: "https://new.carta.tech/ImgChanged/3tk"
---

# ImgChanged(3tk)

notify widgets that image needs to be redrawn

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```

## NAME

Tk\_ImageChanged - notify widgets that image needs to be redrawn

## SYNOPSIS

```
#include <tk.h>

Tk_ImageChanged(imageMaster, x, y, width, height, imageWidth, imageHeight)
```

## ARGUMENTS

- Tk\_ImageMaster *imageMaster* (in)

  Token for image, which was passed to image's *createProc* when the image was created.

- int *x* (in)

  X-coordinate of upper-left corner of region that needs redisplay (measured from upper-left corner of image).

- int *y* (in)

  Y-coordinate of upper-left corner of region that needs redisplay (measured from upper-left corner of image).

- int *width* (in)

  Width of region that needs to be redrawn, in pixels.

- int *height* (in)

  Height of region that needs to be redrawn, in pixels.

- int *imageWidth* (in)

  Current width of image, in pixels.

- int *imageHeight* (in)

  Current height of image, in pixels.

  ```

  ```

## DESCRIPTION

An image manager calls **Tk\_ImageChanged** for an image whenever anything happens that requires the image to be redrawn. As a result of calling **Tk\_ImageChanged**, any widgets using the image are notified so that they can redisplay themselves appropriately. The *imageMaster* argument identifies the image, and *x*, *y*, *width*, and *height* specify a rectangular region within the image that needs to be redrawn. *imageWidth* and *imageHeight* specify the image's (new) size.

An image manager should call **Tk\_ImageChanged** during its *createProc* to specify the image's initial size and to force redisplay if there are existing instances for the image. If any of the pixel values in the image should change later on, **Tk\_ImageChanged** should be called again with *x*, *y*, *width*, and *height* values that cover all the pixels that changed. If the size of the image should change, then **Tk\_ImageChanged** must be called to indicate the new size, even if no pixels need to be redisplayed.

## SEE ALSO

Tk\_CreateImageType

## KEYWORDS

images, redisplay, image size changes