feat(tsf): support user defined preedit display type

- add config option `style/preedit_type(composition|preview)`

RimeWithWeasel/RimeWithWeasel.cpp

@@ -458,20 +458,36 @@ bool RimeWithWeaselHandler::_Respond(UINT session_id, EatLine eat)
 		if (is_composing)
 		{
 			actions.insert("ctx");
-			messages.push_back(std::string("ctx.preedit=") + ctx.composition.preedit + '\n');
-			if (ctx.composition.sel_start <= ctx.composition.sel_end)
+			switch (m_ui->style().preedit_type)
 			{
-				messages.push_back(std::string("ctx.preedit.cursor=") +
-					std::to_string(utf8towcslen(ctx.composition.preedit, ctx.composition.sel_start)) + ',' +
-					std::to_string(utf8towcslen(ctx.composition.preedit, ctx.composition.sel_end)) + '\n');
+			case weasel::PREVIEW:
+				if (ctx.menu.num_candidates > 0)
+				{
+					std::string first = ctx.menu.candidates[0].text;
+					messages.push_back(std::string("ctx.preedit=") + first + '\n');
+					messages.push_back(std::string("ctx.preedit.cursor=") +
+						std::to_string(utf8towcslen(first.c_str(), 0)) + ',' +
+						std::to_string(utf8towcslen(first.c_str(), first.size())) + '\n');
+					break;
+				}
+				// no candidates, fall back to composition
+			case weasel::COMPOSITION:
+				messages.push_back(std::string("ctx.preedit=") + ctx.composition.preedit + '\n');
+				if (ctx.composition.sel_start <= ctx.composition.sel_end)
+				{
+					messages.push_back(std::string("ctx.preedit.cursor=") +
+						std::to_string(utf8towcslen(ctx.composition.preedit, ctx.composition.sel_start)) + ',' +
+						std::to_string(utf8towcslen(ctx.composition.preedit, ctx.composition.sel_end)) + '\n');
+				}
+				break;
 			}
 		}
 		RimeFreeContext(&ctx);
 	}
 
 	// configuration information
 	actions.insert("config");
-	messages.push_back(std::string("config.inline_preedit=") + std::to_string((int) m_ui->style().inline_preedit) + '\n');
+	messages.push_back(std::string("config.inline_preedit=") + std::to_string((int)m_ui->style().inline_preedit) + '\n');
 
 	// summarize
 
@@ -520,6 +536,14 @@ static void _UpdateUIStyle(RimeConfig* config, weasel::UI* ui, bool initialize)
 	{
 		style.inline_preedit = !!inline_preedit;
 	}
+	char preedit_type[20] = { 0 };
+	if (RimeConfigGetString(config, "style/preedit_type", preedit_type, sizeof(preedit_type) - 1))
+	{
+		if (!std::strcmp(preedit_type, "composition"))
+			style.preedit_type = weasel::COMPOSITION;
+		else if (!std::strcmp(preedit_type, "preview"))
+			style.preedit_type = weasel::PREVIEW;
+	}
 	Bool display_tray_icon = False;
 	if (RimeConfigGetBool(config, "style/display_tray_icon", &display_tray_icon) || initialize)
 	{

WeaselTSF/Composition.cpp

@@ -280,7 +280,6 @@ void WeaselTSF::_UpdateComposition(ITfContext *pContext)
 
 	if (ok)
 	{
-		bool composing = _IsComposing();
 		if (!commit.empty())
 		{
 			// 修复顶字上屏的吞字问题：
@@ -289,13 +288,12 @@ void WeaselTSF::_UpdateComposition(ITfContext *pContext)
 			// 此时由于第五码的输入，composition 应是开启的，同时也要在输入处插入顶字。
 			// 这里先关闭上一个字的 composition，然后为后续输入开启一个新 composition。
 			// 有点 dirty 但是 it works ...
-			if (composing) {
+			if (_IsComposing()) {
 				_EndComposition(pContext);
-				composing = false;
 			}
 			_InsertText(pContext, commit);
 		}
-		if (status.composing && !composing)
+		if (status.composing && !_IsComposing())
 		{
 			if (!_fCUASWorkaroundTested)
 			{
@@ -309,12 +307,14 @@ void WeaselTSF::_UpdateComposition(ITfContext *pContext)
 			}
 			_StartComposition(pContext, _fCUASWorkaroundEnabled && !config.inline_preedit);
 		}
-		else if (!status.composing && composing) {
+		else if (!status.composing && _IsComposing())
+		{
 			_EndComposition(pContext);
-			composing = false;
 		}
-		if (composing && config.inline_preedit)
+		if (_IsComposing() && config.inline_preedit)
+		{
 			_ShowInlinePreedit(pContext, context);
+		}
 	}
 }
 

include/WeaselUI.h

@@ -18,11 +18,18 @@ namespace weasel
 		INLINE_PREEDIT_CAPABLE = 1,
 	};
 
+	enum PreeditType
+	{
+		COMPOSITION,
+		PREVIEW
+	};
+
 	struct UIStyle
 	{
 		std::wstring font_face;
 		int font_point;
 		bool inline_preedit;
+		PreeditType preedit_type;
 		bool display_tray_icon;
 		// layout
 		LayoutType layout_type;
@@ -55,6 +62,7 @@ namespace weasel
 		UIStyle() : font_face(), 
 			        font_point(0),
 					inline_preedit(false),
+					preedit_type(COMPOSITION),
 					display_tray_icon(false),
 					layout_type(LAYOUT_VERTICAL),
 					min_width(0),

output/data/weasel.yaml

@@ -14,6 +14,7 @@ style:
   horizontal: false
   fullscreen: false
   inline_preedit: false
+  preedit_type: composition
   display_tray_icon: false
   layout:
     min_width: 160