From 4f461745849c0906e742c3b6afa8a36aeb4493b3 Mon Sep 17 00:00:00 2001
From: nyamatongwe <unknown>
Date: Sat, 6 Sep 2008 10:43:51 +0000
Subject: Changes to improve handling of long lines.

---
 win32/PlatWin.cxx | 135 +++++++++++++++++++++++++++++++++---------------------
 1 file changed, 82 insertions(+), 53 deletions(-)

diff --git a/win32/PlatWin.cxx b/win32/PlatWin.cxx
index 09d97917a..3f0ddd9fb 100644
--- a/win32/PlatWin.cxx
+++ b/win32/PlatWin.cxx
@@ -663,7 +663,32 @@ void SurfaceImpl::Copy(PRectangle rc, Point from, Surface &surfaceSource) {
 		static_cast<SurfaceImpl &>(surfaceSource).hdc, from.x, from.y, SRCCOPY);
 }
 
-const int MAX_US_LEN = 10000;
+// Buffer to hold size strings and string position arrays without always allocating on heap.
+// May sometimes have string too long to allocate on stack. So use a fixed stack-allocated buffer
+// when less than safe size otherwise allocate on heap and free automatically.
+template<typename T, int lengthStandard>
+class VarBuffer {
+	T bufferStandard[lengthStandard];
+public:
+	T *buffer;
+	VarBuffer(size_t length) : buffer(0) {
+		if (length > lengthStandard) {
+			buffer = new T[length];
+		} else {
+			buffer = bufferStandard;
+		}
+	}
+	~VarBuffer() {
+		if (buffer != bufferStandard) {
+			delete []buffer;
+			buffer = 0;
+		}
+	}
+};
+
+const int stackBufferLength = 10000;
+typedef VarBuffer<wchar_t, stackBufferLength> TextWide;
+typedef VarBuffer<int, stackBufferLength> TextPositions;
 
 void SurfaceImpl::DrawTextCommon(PRectangle rc, Font &font_, int ybase, const char *s, int len, UINT fuOptions) {
 	SetFont(font_);
@@ -693,25 +718,22 @@ void SurfaceImpl::DrawTextCommon(PRectangle rc, Font &font_, int ybase, const ch
 		}
 	} else {
 		// Use Unicode calls
-		wchar_t tbuf[MAX_US_LEN];
+		TextWide tbuf(len);
 		int tlen;
 		if (unicodeMode) {
-			tlen = UTF16FromUTF8(s, len, tbuf, MAX_US_LEN);
+			tlen = UTF16FromUTF8(s, len, tbuf.buffer, len);
 		} else {
 			// Support Asian string display in 9x English
-			tlen = ::MultiByteToWideChar(codePage, 0, s, len, NULL, 0);
-			if (tlen > MAX_US_LEN)
-				tlen = MAX_US_LEN;
-			::MultiByteToWideChar(codePage, 0, s, len, tbuf, tlen);
+			tlen = ::MultiByteToWideChar(codePage, 0, s, len, tbuf.buffer, len);
 		}
-		if (!::ExtTextOutW(hdc, x, ybase, fuOptions, &rcw, tbuf, tlen, NULL)) {
+		if (!::ExtTextOutW(hdc, x, ybase, fuOptions, &rcw, tbuf.buffer, tlen, NULL)) {
 			while (tlen > pos) {
 				int seglen = Platform::Minimum(maxSegmentLength, tlen - pos);
-				if (!::ExtTextOutW(hdc, x, ybase, fuOptions, &rcw, tbuf+pos, seglen, NULL)) {
+				if (!::ExtTextOutW(hdc, x, ybase, fuOptions, &rcw, tbuf.buffer+pos, seglen, NULL)) {
 					PLATFORM_ASSERT(false);
 					return;
 				}
-				::GetTextExtentPoint32W(hdc, tbuf+pos, seglen, &sz);
+				::GetTextExtentPoint32W(hdc, tbuf.buffer+pos, seglen, &sz);
 				x += sz.cx;
 				pos += seglen;
 			}
@@ -751,17 +773,16 @@ int SurfaceImpl::WidthText(Font &font_, const char *s, int len) {
 	SetFont(font_);
 	SIZE sz={0,0};
 	if (unicodeMode) {
-		wchar_t tbuf[MAX_US_LEN];
-		int tlen = UTF16FromUTF8(s, len, tbuf, MAX_US_LEN);
-		::GetTextExtentPoint32W(hdc, tbuf, tlen, &sz);
+		TextWide tbuf(len);
+		int tlen = UTF16FromUTF8(s, len, tbuf.buffer, len);
+		::GetTextExtentPoint32W(hdc, tbuf.buffer, tlen, &sz);
 	} else if (IsNT() || (codePage==0) || win9xACPSame) {
 		::GetTextExtentPoint32A(hdc, s, Platform::Minimum(len, maxLenText), &sz);
 	} else {
 		// Support Asian string display in 9x English
-		wchar_t tbuf[MAX_US_LEN];
-		int tlen = ::MultiByteToWideChar(codePage, 0, s, len, NULL, 0);
-		::MultiByteToWideChar(codePage, 0, s, len, tbuf, tlen);
-		::GetTextExtentPoint32W(hdc, tbuf, tlen, &sz);
+		TextWide tbuf(len);
+		int tlen = ::MultiByteToWideChar(codePage, 0, s, len, tbuf.buffer, len);
+		::GetTextExtentPoint32W(hdc, tbuf.buffer, tlen, &sz);
 	}
 	return sz.cx;
 }
@@ -771,20 +792,20 @@ void SurfaceImpl::MeasureWidths(Font &font_, const char *s, int len, int *positi
 	SIZE sz={0,0};
 	int fit = 0;
 	if (unicodeMode) {
-		wchar_t tbuf[MAX_US_LEN];
-		int tlen = UTF16FromUTF8(s, len, tbuf, MAX_US_LEN);
-		int poses[MAX_US_LEN];
+		TextWide tbuf(len);
+		int tlen = UTF16FromUTF8(s, len, tbuf.buffer, len);
+		TextPositions poses(tlen);
 		fit = tlen;
-		if (!::GetTextExtentExPointW(hdc, tbuf, tlen, maxWidthMeasure, &fit, poses, &sz)) {
+		if (!::GetTextExtentExPointW(hdc, tbuf.buffer, tlen, maxWidthMeasure, &fit, poses.buffer, &sz)) {
 			// Likely to have failed because on Windows 9x where function not available
 			// So measure the character widths by measuring each initial substring
 			// Turns a linear operation into a qudratic but seems fast enough on test files
 			for (int widthSS=0; widthSS < tlen; widthSS++) {
-				::GetTextExtentPoint32W(hdc, tbuf, widthSS+1, &sz);
-				poses[widthSS] = sz.cx;
+				::GetTextExtentPoint32W(hdc, tbuf.buffer, widthSS+1, &sz);
+				poses.buffer[widthSS] = sz.cx;
 			}
 		}
-		// Map the widths given for UCS-2 characters back onto the UTF-8 input string
+		// Map the widths given for UTF-16 characters back onto the UTF-8 input string
 		int ui=0;
 		const unsigned char *us = reinterpret_cast<const unsigned char *>(s);
 		int i=0;
@@ -800,7 +821,7 @@ void SurfaceImpl::MeasureWidths(Font &font_, const char *s, int len, int *positi
 				lenChar = 2;
 			}
 			for (unsigned int bytePos=0; (bytePos<lenChar) && (i<len); bytePos++) {
-				positions[i++] = poses[ui];
+				positions[i++] = poses.buffer[ui];
 			}
 			ui++;
 		}
@@ -811,37 +832,47 @@ void SurfaceImpl::MeasureWidths(Font &font_, const char *s, int len, int *positi
 			positions[i++] = lastPos;
 		}
 	} else if (IsNT() || (codePage==0) || win9xACPSame) {
-		if (!::GetTextExtentExPointA(hdc, s, Platform::Minimum(len, maxLenText),
-			maxWidthMeasure, &fit, positions, &sz)) {
-			// Eeek - a NULL DC or other foolishness could cause this.
-			// The least we can do is set the positions to zero!
-			memset(positions, 0, len * sizeof(*positions));
-		} else if (fit < len) {
-			// For some reason, such as an incomplete DBCS character
-			// Not all the positions are filled in so make them equal to end.
-			for (int i=fit;i<len;i++)
-				positions[i] = positions[fit-1];
+		// Zero positions to avoid random behaviour on failure.
+		memset(positions, 0, len * sizeof(*positions));
+		// len may be larger than platform supports so loop over segments small enough for platform
+		int startOffset = 0;
+		while (len > 0) {
+			int lenBlock = Platform::Minimum(len, maxLenText);
+			if (!::GetTextExtentExPointA(hdc, s, lenBlock, maxWidthMeasure, &fit, positions, &sz)) {
+				// Eeek - a NULL DC or other foolishness could cause this.
+				return;
+			} else if (fit < lenBlock) {
+				// For some reason, such as an incomplete DBCS character
+				// Not all the positions are filled in so make them equal to end.
+				for (int i=fit;i<lenBlock;i++)
+					positions[i] = positions[fit-1];
+			} else if (startOffset > 0) {
+				for (int i=0;i<lenBlock;i++)
+					positions[i] += startOffset;
+			}
+			startOffset = positions[lenBlock-1];
+			len -= lenBlock;
+			positions += lenBlock;
+			s += lenBlock;
 		}
 	} else {
 		// Support Asian string display in 9x English
-		wchar_t tbuf[MAX_US_LEN];
-		int tlen = ::MultiByteToWideChar(codePage, 0, s, len, NULL, 0);
-		::MultiByteToWideChar(codePage, 0, s, len, tbuf, tlen);
-
-		int poses[MAX_US_LEN];
+		TextWide tbuf(len);
+		int tlen = ::MultiByteToWideChar(codePage, 0, s, len, tbuf.buffer, len);
+		TextPositions poses(tlen);
 		for (int widthSS=0; widthSS<tlen; widthSS++) {
-			::GetTextExtentPoint32W(hdc, tbuf, widthSS+1, &sz);
-			poses[widthSS] = sz.cx;
+			::GetTextExtentPoint32W(hdc, tbuf.buffer, widthSS+1, &sz);
+			poses.buffer[widthSS] = sz.cx;
 		}
 
 		int ui = 0;
 		for (int i=0;i<len;) {
 			if (::IsDBCSLeadByteEx(codePage, s[i])) {
-				positions[i] = poses[ui];
-				positions[i+1] = poses[ui];
+				positions[i] = poses.buffer[ui];
+				positions[i+1] = poses.buffer[ui];
 				i += 2;
 			} else {
-				positions[i] = poses[ui];
+				positions[i] = poses.buffer[ui];
 				i++;
 			}
 
@@ -1354,10 +1385,9 @@ PRectangle ListBoxX::GetDesiredRect() {
 	SIZE textSize = {0, 0};
 	int len = widestItem ? strlen(widestItem) : 0;
 	if (unicodeMode) {
-		wchar_t tbuf[MAX_US_LEN];
-		len = UTF16FromUTF8(widestItem, len, tbuf, sizeof(tbuf)/sizeof(wchar_t)-1);
-		tbuf[len] = L'\0';
-		::GetTextExtentPoint32W(hdc, tbuf, len, &textSize);
+		TextWide tbuf(len);
+		len = UTF16FromUTF8(widestItem, len, tbuf.buffer, len);
+		::GetTextExtentPoint32W(hdc, tbuf.buffer, len, &textSize);
 	} else {
 		::GetTextExtentPoint32A(hdc, widestItem, len, &textSize);
 	}
@@ -1473,10 +1503,9 @@ void ListBoxX::Draw(DRAWITEMSTRUCT *pDrawItem) {
 		::InsetRect(&rcText, TextInset.x, TextInset.y);
 
 		if (unicodeMode) {
-			wchar_t tbuf[MAX_US_LEN];
-			int tlen = UTF16FromUTF8(text, len, tbuf, sizeof(tbuf)/sizeof(wchar_t)-1);
-			tbuf[tlen] = L'\0';
-			::DrawTextW(pDrawItem->hDC, tbuf, tlen, &rcText, DT_NOPREFIX|DT_END_ELLIPSIS|DT_SINGLELINE|DT_NOCLIP);
+			TextWide tbuf(len);
+			int tlen = UTF16FromUTF8(text, len, tbuf.buffer, len);
+			::DrawTextW(pDrawItem->hDC, tbuf.buffer, tlen, &rcText, DT_NOPREFIX|DT_END_ELLIPSIS|DT_SINGLELINE|DT_NOCLIP);
 		} else {
 			::DrawTextA(pDrawItem->hDC, text, len, &rcText, DT_NOPREFIX|DT_END_ELLIPSIS|DT_SINGLELINE|DT_NOCLIP);
 		}
-- 
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