Tweaks for signature help popup (#2006)

- Add contextSupport
- Add support for `activeParameter` property on `SignatureInformation`
- Allow color schemes to adjust color of currently highlighted parameter
- Small tweaks regarding code style
- Don't close popup while user is typing parameters

Author: jwortmann

docs/src/customization.md

@@ -200,6 +200,7 @@ The color scheme rule only works if the "background" color is different from the
 | ----- | ----------- |
 | `entity.name.function.sighelp.lsp` | Function name in the signature help popup |
 | `variable.parameter.sighelp.lsp` | Function argument in the signature help popup |
+| `variable.parameter.sighelp.active.lsp` | Function argument which is currently highlighted in the signature help popup |
 
 ### Annotations
 

plugin/core/protocol.py

@@ -228,7 +228,8 @@ class SemanticTokenModifiers:
 SignatureInformation = TypedDict('SignatureInformation', {
     'label': str,
     'documentation': Union[str, Dict[str, str]],
-    'parameters': List[ParameterInformation]
+    'parameters': List[ParameterInformation],
+    'activeParameter': int
 }, total=False)
 
 

plugin/core/sessions.py

@@ -254,7 +254,9 @@ def get_initialize_params(variables: Dict[str, str], workspace_folders: List[Wor
         },
         "signatureHelp": {
             "dynamicRegistration": True,
+            "contextSupport": True,
             "signatureInformation": {
+                "activeParameterSupport": True,
                 "documentationFormat": ["markdown", "plaintext"],
                 "parameterInformation": {
                     "labelOffsetSupport": True

plugin/core/signature_help.py

@@ -1,6 +1,5 @@
 from .logging import debug
 from .protocol import SignatureHelp
-from .protocol import SignatureHelpContext
 from .protocol import SignatureInformation
 from .registry import LspTextCommand
 from .typing import Optional, List
@@ -66,26 +65,18 @@ def render(self, view: sublime.View) -> str:
         except IndexError:
             return ""
         formatted = []  # type: List[str]
-        intro = self._render_intro()
-        if intro:
-            formatted.append(intro)
+        if self.has_multiple_signatures():
+            formatted.append(self._render_intro())
         formatted.extend(self._render_label(view, signature))
         formatted.extend(self._render_docs(view, signature))
         return "".join(formatted)
 
-    def context(self, trigger_kind: int, trigger_character: str, is_retrigger: bool) -> SignatureHelpContext:
+    def active_signature_help(self) -> SignatureHelp:
         """
         Extract the state out of this state machine to send back to the language server.
-
-        XXX: Currently unused. Revisit this some time in the future.
         """
         self._state["activeSignature"] = self._active_signature_index
-        return {
-            "triggerKind": trigger_kind,
-            "triggerCharacter": trigger_character,
-            "isRetrigger": is_retrigger,
-            "activeSignatureHelp": self._state
-        }
+        return self._state
 
     def has_multiple_signatures(self) -> bool:
         """Does the current signature help state contain more than one overload?"""
@@ -96,18 +87,13 @@ def select_signature(self, forward: bool) -> None:
         new_index = self._active_signature_index + (1 if forward else -1)
         self._active_signature_index = max(0, min(new_index, len(self._signatures) - 1))
 
-    def active_signature(self) -> SignatureInformation:
-        return self._signatures[self._active_signature_index]
-
-    def _render_intro(self) -> Optional[str]:
-        if len(self._signatures) > 1:
-            fmt = '<p><div style="font-size: 0.9rem"><b>{}</b> of <b>{}</b> overloads ' + \
-                  "(use ↑ ↓ to navigate, press Esc to hide):</div></p>"
-            return fmt.format(
-                self._active_signature_index + 1,
-                len(self._signatures),
-            )
-        return None
+    def _render_intro(self) -> str:
+        fmt = '<p><div style="font-size: 0.9rem"><b>{}</b> of <b>{}</b> overloads ' + \
+              "(use ↑ ↓ to navigate, press Esc to hide):</div></p>"
+        return fmt.format(
+            self._active_signature_index + 1,
+            len(self._signatures),
+        )
 
     def _render_label(self, view: sublime.View, signature: SignatureInformation) -> List[str]:
         formatted = []  # type: List[str]
@@ -118,6 +104,7 @@ def _render_label(self, view: sublime.View, signature: SignatureInformation) ->
         parameters = signature.get("parameters")
         if parameters:
             prev, start, end = 0, 0, 0
+            active_parameter_index = signature.get("activeParameter", self._active_parameter_index)
             for i, param in enumerate(parameters):
                 rawlabel = param["label"]
                 if isinstance(rawlabel, list):
@@ -136,7 +123,7 @@ def _render_label(self, view: sublime.View, signature: SignatureInformation) ->
                     end = start + len(rawlabel)
                 if prev < start:
                     formatted.append(_function(view, label[prev:start]))
-                formatted.append(_parameter(view, label[start:end], i == self._active_parameter_index))
+                formatted.append(_parameter(view, label[start:end], i == active_parameter_index))
                 prev = end
             if end < len(label):
                 formatted.append(_function(view, label[end:]))
@@ -164,7 +151,7 @@ def _parameter_documentation(self, view: sublime.View, signature: SignatureInfor
         if not parameters:
             return None
         try:
-            parameter = parameters[self._active_parameter_index]
+            parameter = parameters[signature.get("activeParameter", self._active_parameter_index)]
         except IndexError:
             return None
         documentation = parameter.get("documentation")
@@ -186,7 +173,8 @@ def _function(view: sublime.View, content: str) -> str:
 
 
 def _parameter(view: sublime.View, content: str, emphasize: bool) -> str:
-    return _wrap_with_scope_style(view, content, "variable.parameter.sighelp.lsp", emphasize)
+    scope = "variable.parameter.sighelp.active.lsp" if emphasize else "variable.parameter.sighelp.lsp"
+    return _wrap_with_scope_style(view, content, scope, emphasize)
 
 
 def _wrap_with_scope_style(view: sublime.View, content: str, scope: str, emphasize: bool) -> str:

plugin/documents.py

@@ -14,6 +14,8 @@
 from .core.protocol import Range
 from .core.protocol import Request
 from .core.protocol import SignatureHelp
+from .core.protocol import SignatureHelpContext
+from .core.protocol import SignatureHelpTriggerKind
 from .core.registry import best_session
 from .core.registry import windows
 from .core.sessions import AbstractViewListener
@@ -466,10 +468,28 @@ def do_signature_help_async(self, manual: bool) -> None:
         last_char = previous_non_whitespace_char(self.view, pos)
         if manual or last_char in triggers:
             self.purge_changes_async()
-            params = text_document_position_params(self.view, pos)
+            position_params = text_document_position_params(self.view, pos)
+            context_params = {}  # type: SignatureHelpContext
+            if manual:
+                context_params["triggerKind"] = SignatureHelpTriggerKind.Invoked
+            else:
+                context_params["triggerKind"] = SignatureHelpTriggerKind.TriggerCharacter
+                context_params["triggerCharacter"] = last_char
+            context_params["isRetrigger"] = self._sighelp is not None
+            if self._sighelp:
+                context_params["activeSignatureHelp"] = self._sighelp.active_signature_help()
+            params = {
+                "textDocument": position_params["textDocument"],
+                "position": position_params["position"],
+                "context": context_params
+            }
             language_map = session.markdown_language_id_to_st_syntax_map()
             request = Request.signatureHelp(params, self.view)
             session.send_request_async(request, lambda resp: self._on_signature_help(resp, pos, language_map))
+        elif self.view.match_selector(pos, "meta.function-call.arguments"):
+            # Don't force close the signature help popup while the user is typing the parameters.
+            # See also: https://github.com/sublimehq/sublime_text/issues/5518
+            pass
         else:
             # TODO: Refactor popup usage to a common class. We now have sigHelp, completionDocs, hover, and diags
             # all using a popup. Most of these systems assume they have exclusive access to a popup, while in
@@ -510,7 +530,7 @@ def _show_sighelp_popup(self, content: str, point: int) -> None:
         show_lsp_popup(
             self.view,
             content,
-            flags=sublime.HIDE_ON_MOUSE_MOVE_AWAY | sublime.COOPERATE_WITH_AUTO_COMPLETE,
+            flags=sublime.COOPERATE_WITH_AUTO_COMPLETE,
             location=point,
             on_hide=self._on_sighelp_hide,
             on_navigate=self._on_sighelp_navigate)