Preserve the selected view on scenario result updates (#1776)

Previously, we always reverted back to the table view when the
scenario results changed. This PR changes this to preserve the
selected view.

I’ve also tested that this does not break backwards compatibility: If
you use the newer extension with an older SDK, you will get the
previous behavior of reverting to the table view and you can still
switch by clicking on the button.

Fixes #1675

compiler/scenario-service/client/src/DA/Daml/LF/PrettyScenario.hs

@@ -920,13 +920,38 @@ renderScenarioResult world res = TL.toStrict $ Blaze.renderHtml $ do
 
 javascript :: T.Text
 javascript = T.unlines
-  [ "function show_archived_changed() {"
+  [ "const vscode = acquireVsCodeApi();"
+  , "function show_archived_changed() {"
   , "  document.body.classList.toggle('hide_archived', !document.getElementById('show_archived').checked);"
   , "}"
   , "function toggle_view() {"
   , "  document.body.classList.toggle('hide_transaction');"
   , "  document.body.classList.toggle('hide_table');"
+  , "  vscode.postMessage({"
+  , "    'command': 'selected_view',"
+  , "    'value': document.body.classList.contains('hide_transaction') ? 'table' : 'transaction'"
+  , "  });"
   , "}"
+  , "window.addEventListener('message', event => {"
+  , "  const message = event.data;"
+  , "  switch (message.command) {"
+  , "    case 'select_view':"
+  , "      switch (message.value) {"
+  , "        case 'transaction':"
+  , "          document.body.classList.remove('hide_transaction');"
+  , "          document.body.classList.add('hide_table');"
+  , "          break;"
+  , "        case 'table':"
+  , "          document.body.classList.add('hide_transaction');"
+  , "          document.body.classList.remove('hide_table');"
+  , "          break;"
+  , "        default:"
+  , "          console.log('Unexpected value for select_view: ' + message.value);"
+  , "          break;"
+  , "      }"
+  , "      break;"
+  , "  }"
+  , "});"
   ]
 
 stylesheet :: T.Text

daml-foundations/daml-tools/daml-extension/src/extension.ts

@@ -266,8 +266,12 @@ namespace DamlWorkspaceValidationsNotification {
 }
 
 class VirtualResourceManager {
+    // Mapping from URIs to the web view panel
     private _panels: Map<string, vscode.WebviewPanel> = new Map<string, vscode.WebviewPanel>();
+    // Mapping from URIs to the HTML content of the webview
     private _panelContents: Map<string, string> = new Map<string, string>();
+    // Mapping from URIs to selected view
+    private _panelStates: Map<string, string> = new Map<string, string>();
     private _client: LanguageClient;
     private _disposables: vscode.Disposable[] = [];
 
@@ -316,6 +320,15 @@ class VirtualResourceManager {
             null,
             this._disposables
         );
+        panel.webview.onDidReceiveMessage(
+            message => {
+                switch (message.command) {
+                    case 'selected_view':
+                        this._panelStates.set(uri, message.value);
+                        break;
+                }
+            }
+        );
         this._panels.set(uri, panel);
         panel.webview.html = this._panelContents.get(uri) || '';
     }
@@ -325,6 +338,10 @@ class VirtualResourceManager {
         const panel = this._panels.get(uri);
         if (panel) {
             panel.webview.html = contents;
+            const panelState = this._panelStates.get(uri);
+            if (panelState) {
+                panel.webview.postMessage({command: 'select_view', value: panelState});
+            };
         }
     }
 

unreleased.rst

@@ -9,3 +9,9 @@ This page contains release notes for the SDK.
 HEAD — ongoing
 --------------
 
+DAML Studio
+~~~~~~~~~~~
+
+- The selected view for scenario results (table or transaction) is now
+  preserved when the scenario results are updated.
+  See `#1675 <https://github.com/digital-asset/daml/issues/1675>`__.