Lots of work on the lua read-eval-print loop

Docs/TODO-List.md

@@ -1,20 +1,10 @@
 
-* UE Wingman rename functions.
-* ue Wingman 'structprop' doesn't work for UWingXXXRef types, or for Widget slots.  It needs to be implemented on top of getdetails.
-* In the console, do not allow multi-line lua expressions unless it's something that reasonably should be multi-line, like a function definition or an if-statement.
 
-* Keyboard Event Handling
-
-* Menus
 
 * Skeletal Mesh Tangible
 
 * Implement Interactive Temporary Variables
 
-* A better text console
-
-* Get rid of 3x3 Gridpanel stuff
-
 * Object-Oriented Lua Support
 
 

Source/Integration/UtilityLibrary.cpp

@@ -10,6 +10,8 @@
 #include "Kismet/GameplayStatics.h"
 #include "Blueprint/UserWidget.h"
 #include "Components/GridPanel.h"
+#include "Components/CanvasPanelSlot.h"
+#include "Components/Widget.h"
 #include "InputMappingContext.h"
 #include "EnhancedInputComponent.h"
 #include "Animation/AnimSequenceBase.h"
@@ -156,65 +158,28 @@ bool UlxUtilityLibrary::LineTraceThroughPixel(const APlayerController* PlayerCon
 	return false;
 }
 
-void UlxUtilityLibrary::SetPositionOfGridPanelMiddleCell(UGridPanel *GridPanel, FVector2D UpperLeftXY, FVector2D LowerRightXY)
+void UlxUtilityLibrary::ConfigureCanvasPanelSlot(UObject *Target, FAnchors Anchors, FVector2D Position, FVector2D Size, FVector2D Alignment, bool SizeToContent)
 {
-	if ((GridPanel == nullptr) || (GridPanel->ColumnFill.Num() != 3) || (GridPanel->RowFill.Num() != 3))
+	UCanvasPanelSlot *CanvasSlot = Cast<UCanvasPanelSlot>(Target);
+	if (CanvasSlot == nullptr)
 	{
-		UE_LOG(LogBlueprint, Error, TEXT("SetPositionOfGridPanelMiddleCell only works on 3x3 GridPanels."));
+		UWidget *Widget = Cast<UWidget>(Target);
+		if (Widget != nullptr)
+		{
+			CanvasSlot = Cast<UCanvasPanelSlot>(Widget->Slot);
+		}
+	}
+	if (CanvasSlot == nullptr)
+	{
+		UE_LOG(LogBlueprint, Error, TEXT("ConfigureCanvasPanelSlot: object is not a CanvasPanelSlot, and is not a Widget in a CanvasPanel."));
 		return;
 	}
 
-	if ((LowerRightXY.X < UpperLeftXY.X) || (LowerRightXY.Y < UpperLeftXY.Y))
+	CanvasSlot->SetAnchors(Anchors);
-	{
+	CanvasSlot->SetAlignment(Alignment);
-		UE_LOG(LogBlueprint, Error, TEXT("LowerRightXY must be greater than or equal to UpperLeftXY"));
+	CanvasSlot->SetPosition(Position);
-		return;
+	CanvasSlot->SetSize(Size);
-	}
+	CanvasSlot->SetAutoSize(SizeToContent);
-
-	UpperLeftXY.X = FMath::Clamp(UpperLeftXY.X, 0.0f, 1.0f);
-	UpperLeftXY.Y = FMath::Clamp(UpperLeftXY.Y, 0.0f, 1.0f);
-	LowerRightXY.X = FMath::Clamp(LowerRightXY.X, 0.0f, 1.0f);
-	LowerRightXY.Y = FMath::Clamp(LowerRightXY.Y, 0.0f, 1.0f);
-
-	GridPanel->SetRowFill(0, UpperLeftXY.Y);
-	GridPanel->SetRowFill(1, LowerRightXY.Y - UpperLeftXY.Y);
-	GridPanel->SetRowFill(2, 1.0 - LowerRightXY.Y);
-
-	GridPanel->SetColumnFill(0, UpperLeftXY.X);
-	GridPanel->SetColumnFill(1, LowerRightXY.X - UpperLeftXY.X);
-	GridPanel->SetColumnFill(2, 1.0 - LowerRightXY.X);
-}
-
-void UlxUtilityLibrary::GetPositionOfGridPanelMiddleCell(UGridPanel *GridPanel, FVector2D &UpperLeftXY, FVector2D &LowerRightXY)
-{
-	TArray<float> &Col = GridPanel->ColumnFill;
-	TArray<float> &Row = GridPanel->RowFill;
-
-	// Set default return value for error situations.
-	UpperLeftXY.X = 0.0;
-	LowerRightXY.X = 1.0;
-	UpperLeftXY.Y = 0.0;
-	LowerRightXY.Y = 1.0;
-
-	if ((GridPanel == nullptr) || (Row.Num() != 3) || (Col.Num() != 3))
-	{
-		UE_LOG(LogBlueprint, Error, TEXT("SetPositionOfGridPanelMiddleCell only works on 3x3 GridPanels."));
-		return;
-	}
-
-	double TotalX = Col[0] + Col[1] + Col[2];
-	double TotalY = Row[0] + Row[1] + Row[2];
-	
-	if (TotalX > 0)
-	{
-		UpperLeftXY.X = Col[0] / TotalX;
-		LowerRightXY.X = (Col[0] + Col[1]) / TotalX;
-	}
-
-	if (TotalY > 0)
-	{
-		UpperLeftXY.Y = Row[0] / TotalY;
-		LowerRightXY.Y = (Row[0] + Row[1]) / TotalY;
-	}
 }
 
 ElxUsedOrNotUsed UlxUtilityLibrary::IsKeyUsedByMappingContext(const FKey &Key, const UInputMappingContext *MappingContext)

Source/Integration/UtilityLibrary.h

@@ -7,6 +7,7 @@
 #include "Input/Events.h"
 #include "Common.h"
 #include "Kismet/BlueprintFunctionLibrary.h"
+#include "Components/CanvasPanelSlot.h"
 
 #include "UtilityLibrary.generated.h"
 
@@ -91,51 +92,15 @@ public:
 			ETraceTypeQuery TraceChannel, bool bTraceComplex, EDrawDebugTrace::Type DrawDebugType, bool bIgnorePlayerPawn,
 			const TArray<AActor*>& ActorsToIgnore, FHitResult& HitResult);
 
-	// Set Position of GridPanel Middle Cell
-	//
-	// Sometimes, you want to specify the position of a widget, and you
-	// don't want to specify the position in slate units, instead, you
-	// want to specify the position using fractions: ie, (0,0) is the
-	// upper left corner of the screen, and (1,1) is the lower-right corner.
-	//
-	// One way to accomplish this is to put your widget in the middle cell
-	// of a 3x3 GridPanel.  Then, you can position it by adjusting the grid
-	// fill rules.  This utility routine can do the math necessary to
-	// correctly populate those fill rules.
-	//
-	// This routine must be passed a 3x3 GridPanel.  This will reposition
-	// the middle cell.  You must specify the upper-left and lower-right
-	// corners of the middle cell as fractions between (0,0) and (1,1).
-	//
-	// Be aware that if the content of a grid cell overflows the amount of
-	// space allocated for it, then the grid will adjust to make room.
-	// But that will mean that the grid is no longer faithful to the 
-	// positions specified in its fill rules.  One way to ensure that the
-	// grid remains faithful to its fill rules is to put an Overlay
-	// into the GridPanel cell, then put -1000 padding into the
-	// Overlay's GridPanel slot, then put +1000 padding into the Overlay
-	// slot.  The two paddings cancel each other out, leaving the item in
-	// the Overlay at the originally-intended position.  But if the item
-	// in the overlay overflows, it doesn't cause the Grid to deform.
-	// Instead, the item exceeds the bounds of the grid cell, but it leaves
-	// the grid cell where it belongs.
-	// 
-	UFUNCTION(BlueprintCallable, Category="Widget")
-	static void SetPositionOfGridPanelMiddleCell(UGridPanel *GridPanel, FVector2D UpperLeftXY, FVector2D LowerRightXY);
 
-	// Get Position of GridPanel Middle Cell
+	// Configure a CanvasPanelSlot's parameters in a single call.
 	//
-	// The routine must be passed a 3x3 GridPanel.  This will return the
+	// Target must be either a UCanvasPanelSlot directly, or a UWidget whose
-	// position of the middle cell of the gridpanel, expressed on a scale
+	// Slot is a UCanvasPanelSlot. If it is neither, logs an error and
-	// from (0,0) to (1,1).
+	// does nothing.
-	// 
-	// The numbers returned by this routine are based entirely on the
-	// GridPanel fill rules.  If an item in the grid is overflowing its
-	// allocated space, causing the grid to deform, then that won't be
-	// reflected in the output of this routine.
 	//
-	UFUNCTION(BlueprintPure, Category="Widget")
+	UFUNCTION(BlueprintCallable, Category = "Widget", meta = (SizeToContent = "true"))
-	static void GetPositionOfGridPanelMiddleCell(UGridPanel *GridPanel, FVector2D &UpperLeftXY, FVector2D &LowerRightXY);
+	static void ConfigureCanvasPanelSlot(UObject *Target, FAnchors Anchors, FVector2D Position, FVector2D Size, FVector2D Alignment, bool SizeToContent);
 
 	// Check if a given key is used by the specified mapping context.
 	//

luprex/cpp/core/luastack.cpp

@@ -336,7 +336,7 @@ eng::string LuaCoreStack::load(LuaSlot result, std::string_view code, std::strin
         const char *str = lua_tolstring(L_, -1, &len);
         eng::string message(str, len);
         lua_pop(L_, 1);
-        if (sv::has_suffix(message, "near <eof>"))
+        if (sv::has_suffix(message, "near <eof>") && sv::is_possible_long_lua_expression(code))
         {
             message = "truncated lua";
         }

luprex/cpp/core/printbuffer.cpp

@@ -192,7 +192,6 @@ bool PrintChanneler::channel(const PrintBuffer *printbuffer, StreamBuffer *sb) {
         line_ = printbuffer->first_line();
     }
     while (line_ < printbuffer->first_unchecked()) {
-        sb->write_bytes("|");
         sb->write_bytes(printbuffer->nth(line_));
         sb->write_bytes("\n");
         line_ += 1;

luprex/cpp/core/util.cpp

@@ -200,6 +200,24 @@ bool is_lua_comment(string_view s) {
     return s.substr(start, 2) == "--";
 }
 
+bool is_possible_long_lua_expression(string_view s) {
+    read_space(s);
+    string_view id = read_lua_identifier(s);
+    if (id.empty()) return false;
+    if ((id == "function") || (id == "if") || (id == "while") || (id == "for") || (id == "repeat") || (id == "do")) return true;
+    if (id == "local")
+    {
+        read_space(s);
+        id = read_lua_identifier(s);
+    }
+    read_space(s);
+    read_prefix(s, "="); // If not present, returns false but we continue anyway.
+    read_space(s);
+    if (has_prefix(s, "[")) return true;
+    if (has_prefix(s, "(")) return true;
+    return false;
+}
+
 bool is_whitespace(string_view s) {
     for (int i = 0; i < int(s.size()); i++) {
         if (!ascii_isspace(s[i])) {

luprex/cpp/core/util.hpp

@@ -106,6 +106,14 @@ bool is_lua_classname(string_view s);
 // Return true if the line of code is a lua comment.
 bool is_lua_comment(string_view s);
 
+// Return true if the line of code could be the beginning of a long expression.
+// In a read-eval-print loop, if the user types something like "function foo",
+// that's not a complete lua expression.  But we don't want to just print an error,
+// we want to give the user a chance to continue typing so that he can turn it
+// into a complete lua expression.  This function returns true if the string looks
+// like the beginning of a long lua expression.  This is only a heuristic.
+bool is_possible_long_lua_expression(string_view s);
+
 // Return true if the line is entirely whitespace.
 bool is_whitespace(string_view s);
 

luprex/cpp/core/world-core.cpp

@@ -1071,6 +1071,10 @@ void World::run_scheduled_threads() {
                     PrettyPrint::Indented().print(LSCO, LuaSpecial(i), &lthread_prints_);
                     lthread_prints_ << std::endl;
                 }
+                if (lthread_prints_.view().empty())
+                {
+                    lthread_prints_ << "ok\n";
+                }
             }
         } else if (status == LUA_YIELD) {
             if (is_authoritative()) {

luprex/lua/login.lua

@@ -40,6 +40,7 @@ function cube.lookmenu(add)
     add("Cube Hi", function () dprint("Doing Cube Hi") end)
     add("Cube Bye", function () dprint("Doing Cube Bye") end)
     add("Cube Yo", function () dprint("Doing Cube Yo") end)
+    add("Cube Z", function () dprint("Doing Cube Z") end)
 end
 
 function sphere.lookhotkeys(add)