Dismiss the PDF view controller when the view component is unmounted to avoid orphan popovers

[radazzouz]

Solves #277

---

Details

How to Reproduce:

• Modify Catalog.ios.js like this:

class ConfiguredPDFViewComponent extends Component {
+ componentDidMount = () => {
+   setTimeout(() => {
+     this.props.navigation.navigate("Catalog");
+   }, 10000);
+ };
  render() {
    return (
      <View style={{ flex: 1 }}>
        <PSPDFKitView
          document={"PDFs/Annual Report.pdf"}
          configuration={{
            backgroundColor: processColor("lightgrey"),
            showThumbnailBar: "scrubberBar",
            showDocumentLabel: false,
            useParentNavigationBar: false,
            allowToolbarTitleChange: false
          }}
          toolbarTitle={"Custom Title"}
+         leftBarButtonItems={["settingsButtonItem"]}
          style={{ flex: 1, color: pspdfkitColor }}
        />
      </View>
    );
  }
}

• Open the "PDF View Component" example.
• Tap on the settings left bar button item and wait a few seconds for the navigation (for the component to be unmounted).

Expected:

The popover should disappear.

Actual:

The popover is still there even if the pdf view controller has been dismissed.

Before	After

Acceptance Criteria

• Fix the issue.
• When approved, right before merging, rebase with master and increment the package version in package.json, package-lock.json, and samples/Catalog/package.json (see example commit: 1bf805f).
• Create a new release (and tag) with the new package version (see https://github.com/PSPDFKit/react-native/releases).

[steviki]

LGTM!

[steipete]

@radazzouz Please add a comment to that, so we know what this was for.

[radazzouz]

Good idea! Done in #287