# Maximum Open Projects Sample [![JetBrains IntelliJ Platform SDK Docs](https://jb.gg/badges/docs.svg)][docs]
*Reference: [Plugin Services in IntelliJ SDK Docs][docs:plugin_services]*

## Quickstart

Maximum Open Projects Sample implements a `ProjectManagerListener` with two methods applied to check if the current projects have been opened or closed.
Each method refers to the `ProjectCountingService` service registered as an `applicationService` extension point.
It provides methods to increase and decrease the global counter of the currently opened projects in the IDE.
After opening each one, a message dialog is presented to the user with the current number.

### Extension Points

| Name                              | Implementation                                        | Extension Point Class |
| --------------------------------- | ----------------------------------------------------- | --------------------- |
| `com.intellij.applicationService` | [ProjectCountingService][file:ProjectCountingService] |                       |

*Reference: [Plugin Extension Points in IntelliJ SDK Docs][docs:ep]*

### Application Listeners

| Name     | Implementation                                            | Extension Point Class                                |
| -------- | --------------------------------------------------------- | ---------------------------------------------------- |
| listener | [ProjectOpenCloseListener][file:ProjectOpenCloseListener] | [ProjectManagerListener][sdk:ProjectManagerListener] |

*Reference: [Plugin Listeners in IntelliJ SDK Docs][docs:listeners]*

[docs]: https://www.jetbrains.org/intellij/sdk/docs
[docs:plugin_services]: https://jetbrains.org/intellij/sdk/docs/basics/plugin_structure/plugin_services.html
[docs:ep]: https://www.jetbrains.org/intellij/sdk/docs/basics/plugin_structure/plugin_extensions.html
[docs:listeners]: https://jetbrains.org/intellij/sdk/docs/basics/plugin_structure/plugin_listeners.html

[file:ProjectCountingService]: ./src/main/java/org/intellij/sdk/maxOpenProjects/ProjectCountingService.java
[file:ProjectOpenCloseListener]: ./src/main/java/org/intellij/sdk/maxOpenProjects/ProjectOpenCloseListener.java

[sdk:ProjectManagerListener]: upsource:///platform/projectModel-api/src/com/intellij/openapi/project/ProjectManagerListener.java