Various fixes.

Fixed tab size calculatio issue.
Fixed overwrite mode cursor width issue.

TextEditor.cpp

diff --git a/TextEditor.cpp b/TextEditor.cpp
index 2909ca6..1eb8435 100644
--- a/TextEditor.cpp
+++ b/TextEditor.cpp
@@ -346,7 +346,7 @@
 				auto fontScale = ImGui::GetFontSize() / ImGui::GetFont()->FontSize;

 				float spaceSize = ImGui::GetFont()->CalcTextSizeA(ImGui::GetFontSize(), FLT_MAX, -1.0f, " ").x;

 				float oldX = columnX;

-				columnX = (1.0f * fontScale + std::floor((1.0f + columnX)) / (float(mTabSize) * spaceSize)) * (float(mTabSize) * spaceSize);

+				columnX = (1.0f * fontScale + std::floor((1.0f + columnX) / (float(mTabSize) * spaceSize))) * (float(mTabSize) * spaceSize);

 				columnWidth = columnX - oldX;

 				columnCoord++;

 			}

@@ -912,11 +912,11 @@
 			auto lineNoWidth = ImGui::GetFont()->CalcTextSizeA(ImGui::GetFontSize(), FLT_MAX, -1.0f, buf, nullptr, nullptr).x;

 			drawList->AddText(ImVec2(lineStartScreenPos.x + mTextStart - lineNoWidth, lineStartScreenPos.y), mPalette[(int)PaletteIndex::LineNumber], buf);

 

-			// Highlight the current line (where the cursor is)

 			if (mState.mCursorPosition.mLine == lineNo)

 			{

 				auto focused = ImGui::IsWindowFocused();

 

+				// Highlight the current line (where the cursor is)

 				if (!HasSelection())

 				{

 					auto end = ImVec2(start.x + contentSize.x + scrollX, start.y + mCharAdvance.y);

@@ -924,8 +924,7 @@
 					drawList->AddRect(start, end, mPalette[(int)PaletteIndex::CurrentLineEdge], 1.0f);

 				}

 

-				float cx = TextDistanceToLineStart(mState.mCursorPosition);

-

+				// Render the cursor

 				if (focused)

 				{

 					static auto timeStart = std::chrono::system_clock::now();

@@ -934,8 +933,28 @@
 					auto elapsed = std::chrono::duration_cast<std::chrono::milliseconds>(diff).count();

 					if (elapsed > 400)

 					{

+						float width = 1.0f;

+						auto cindex = GetCharacterIndex(mState.mCursorPosition);

+						float cx = TextDistanceToLineStart(mState.mCursorPosition);

+

+						if (mOverwrite && cindex < (int)line.size())

+						{

+							auto c = line[cindex].mChar;

+							if (c == '\t')

+							{

+								auto x = (1.0f * fontScale + std::floor((1.0f + cx) / (float(mTabSize) * spaceSize))) * (float(mTabSize) * spaceSize);

+								width = x - cx;

+							}

+							else

+							{

+								char buf[2];

+								buf[0] = line[cindex].mChar;

+								buf[1] = '\0';

+								width = ImGui::GetFont()->CalcTextSizeA(ImGui::GetFontSize(), FLT_MAX, -1.0f, buf).x;

+							}

+						}

 						ImVec2 cstart(textScreenPos.x + cx, lineStartScreenPos.y);

-						ImVec2 cend(textScreenPos.x + cx + (mOverwrite ? mCharAdvance.x : 1.0f), lineStartScreenPos.y + mCharAdvance.y);

+						ImVec2 cend(textScreenPos.x + cx + width, lineStartScreenPos.y + mCharAdvance.y);

 						drawList->AddRectFilled(cstart, cend, mPalette[(int)PaletteIndex::Cursor]);

 						if (elapsed > 800)

 							timeStart = timeEnd;

@@ -2323,7 +2342,7 @@
 	{

 		if (line[it].mChar == '\t')

 		{

-			distance = (1.0f * fontScale + std::floor((1.0f + distance)) / (float(mTabSize) * spaceSize)) * (float(mTabSize) * spaceSize);

+			distance = (1.0f * fontScale + std::floor((1.0f + distance) / (float(mTabSize) * spaceSize))) * (float(mTabSize) * spaceSize);

 			++it;

 		}

 		else