Add an action to upload media files according to MSC4039 (#11311)

Signed-off-by: Dominik Henneke <dominik.henneke@nordeck.net>

src/components/views/dialogs/ModalWidgetDialog.tsx

@@ -136,6 +136,7 @@ export default class ModalWidgetDialog extends React.PureComponent<IProps, IStat
             clientId: ELEMENT_CLIENT_ID,
             clientTheme: SettingsStore.getValue("theme"),
             clientLanguage: getUserLanguage(),
+            baseUrl: MatrixClientPeg.safeGet().baseUrl,
         });
 
         const parsed = new URL(templated);

src/stores/widgets/StopGapWidget.ts

@@ -218,6 +218,7 @@ export class StopGapWidget extends EventEmitter {
             clientTheme: SettingsStore.getValue("theme"),
             clientLanguage: getUserLanguage(),
             deviceId: this.client.getDeviceId() ?? undefined,
+            baseUrl: this.client.baseUrl,
         };
         const templated = this.mockWidget.getCompleteUrl(Object.assign(defaults, fromCustomisation), opts?.asPopout);
 

src/stores/widgets/StopGapWidgetDriver.ts

@@ -32,6 +32,7 @@ import {
     WidgetEventCapability,
     WidgetKind,
     ISearchUserDirectoryResult,
+    IGetMediaConfigResult,
 } from "matrix-widget-api";
 import {
     ClientEvent,
@@ -523,4 +524,18 @@ export class StopGapWidgetDriver extends WidgetDriver {
             })),
         };
     }
+
+    public async getMediaConfig(): Promise<IGetMediaConfigResult> {
+        const client = MatrixClientPeg.safeGet();
+
+        return await client.getMediaConfig();
+    }
+
+    public async uploadFile(file: XMLHttpRequestBodyInit): Promise<{ contentUri: string }> {
+        const client = MatrixClientPeg.safeGet();
+
+        const uploadResult = await client.uploadContent(file);
+
+        return { contentUri: uploadResult.content_uri };
+    }
 }