PtHold, PtRelease

Gamma/Photon: Using Gamma™ with the Photon microGUIŽ, Version 4.0
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# `PtHold`, `PtRelease`

`PtHold`, `PtRelease` -- hold/release the issue of all Photon events to the Photon server.

## Syntax

    PtHold ()
    PtRelease ()

## Arguments

`none`

## Returns

A global hold count value.

## Description

`PtHold` prevents all Photon events from being issued to the Photon server. This is useful when a program makes a large number of changes to either overlapping widgets or widgets contained in the same container. Using `PtHold` can prevent the container from being re-drawn after each change. Normally, `PhEventNext` is called within the Gamma `next_event` function, allowing events to be processed. Using `PtHold` prevents `PhEventNext` from being executed within `next_event`.

`PtHold` will not stop all Photon events from being submitted to the Photon server indefinitly. Once the application's draw buffer is full, the events will be sent to the Photon server, regardless of `PtHold`.

Each time `PtHold` is called, the global hold count increases by one. This hold count is decreased by one each time `PtRelease` is called. When the global hold count decreases to 0, the held Photon events are submitted to the Photon server through the event loop once again. Thus `PtHold` and `PtRelease` are typically called conjointly.

## See Also

In Photon documentation: PtHold, PtRelease.

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