Omit mag slider in TIFF export if only one mag is available (#8297)

* only display mag slider if there are multiple mags and fix additional axes check

* add changelog

* improve if clause

* address review: remove <br />

Author: knollengewaechs

CHANGELOG.unreleased.md

@@ -39,6 +39,7 @@ For upgrade instructions, please check the [migration guide](MIGRATIONS.released
 - Fixed some layout issues in the upload view. [#8231](https://github.com/scalableminds/webknossos/pull/8231)
 - Fixed `FATAL: role "postgres" does not exist` error message in Docker compose. [#8240](https://github.com/scalableminds/webknossos/pull/8240)
 - Fixed the Zarr 3 implementation not accepting BytesCodec without "configuration" key. [#8282](https://github.com/scalableminds/webknossos/pull/8282)
+- Removed the magnification slider for the TIFF export within the download modal if only one magnification is available for the selected layer. [#8297](https://github.com/scalableminds/webknossos/pull/8297)
 
 ### Removed
 - Removed support for HTTP API versions 3 and 4. [#8075](https://github.com/scalableminds/webknossos/pull/8075)

frontend/javascripts/oxalis/view/action-bar/download_modal_view.tsx

@@ -576,6 +576,8 @@ function _DownloadModalView({
     </>
   );
 
+  const onlyOneMagAvailable = selectedLayerMagInfo.getMagList().length === 1;
+
   const tiffExportTab = (
     <>
       <Row>
@@ -642,7 +644,7 @@ function _DownloadModalView({
             style={{ width: "100%" }}
           />
           {boundingBoxCompatibilityAlerts}
-          {selectedLayerInfos.additionalAxes != null && (
+          {(selectedLayerInfos.additionalAxes?.length || 0) > 0 && (
             <Row>
               <Divider
                 style={{
@@ -670,23 +672,26 @@ function _DownloadModalView({
           >
             Mag
           </Divider>
-          <Row>
-            <Col span={19}>
-              <MagSlider magnificationInfo={selectedLayerMagInfo} value={mag} onChange={setMag} />
-            </Col>
-            <Col
-              span={5}
-              style={{ display: "flex", justifyContent: "flex-end", alignItems: "center" }}
-            >
-              {mag.join("-")}
-            </Col>
-          </Row>
+          {!onlyOneMagAvailable && (
+            <Row>
+              <Col span={19}>
+                <MagSlider magnificationInfo={selectedLayerMagInfo} value={mag} onChange={setMag} />
+              </Col>
+              <Col
+                span={5}
+                style={{ display: "flex", justifyContent: "flex-end", alignItems: "center" }}
+              >
+                {mag.join("-")}
+              </Col>
+            </Row>
+          )}
           <Text
             style={{
               margin: "0 6px 12px",
               display: "block",
             }}
           >
+            {onlyOneMagAvailable && <div>{mag.join("-")}</div>}
             Estimated file size:{" "}
             {estimateFileSize(selectedLayer, mag, selectedBoundingBox.boundingBox, exportFormat)}
             <br />