// Scintilla source code edit control
/** @file Editor.cxx
 ** Main code for the edit control.
 **/
// Copyright 1998-2004 by Neil Hodgson <neilh@scintilla.org>
// The License.txt file describes the conditions under which this software may be distributed.

#include <stdlib.h>
#include <string.h>
#include <stdio.h>
#include <ctype.h>

#include "Platform.h"

#ifndef PLAT_QT
#define INCLUDE_DEPRECATED_FEATURES
#endif
#include "Scintilla.h"

#include "ContractionState.h"
#include "SVector.h"
#include "SplitVector.h"
#include "Partitioning.h"
#include "CellBuffer.h"
#include "KeyMap.h"
#include "Indicator.h"
#include "XPM.h"
#include "LineMarker.h"
#include "Style.h"
#include "ViewStyle.h"
#include "CharClassify.h"
#include "Document.h"
#include "Editor.h"

/*
	return whether this modification represents an operation that
	may reasonably be deferred (not done now OR [possibly] at all)
*/
static bool CanDeferToLastStep(const DocModification& mh) {
	if (mh.modificationType & (SC_MOD_BEFOREINSERT|SC_MOD_BEFOREDELETE))
		return true;	// CAN skip
	if (!(mh.modificationType & (SC_PERFORMED_UNDO|SC_PERFORMED_REDO)))
		return false;	// MUST do
	if (mh.modificationType & SC_MULTISTEPUNDOREDO)
		return true;	// CAN skip
	return false;		// PRESUMABLY must do
}

static bool CanEliminate(const DocModification& mh) {
	return
		(mh.modificationType & (SC_MOD_BEFOREINSERT|SC_MOD_BEFOREDELETE)) != 0;
}

/*
	return whether this modification represents the FINAL step
	in a [possibly lengthy] multi-step Undo/Redo sequence
*/
static bool IsLastStep(const DocModification& mh) {
	return
		(mh.modificationType & (SC_PERFORMED_UNDO|SC_PERFORMED_REDO)) != 0
		&& (mh.modificationType & SC_MULTISTEPUNDOREDO) != 0
		&& (mh.modificationType & SC_LASTSTEPINUNDOREDO) != 0
		&& (mh.modificationType & SC_MULTILINEUNDOREDO) != 0;
}

Caret::Caret() :
active(false), on(false), period(500) {}

Timer::Timer() :
ticking(false), ticksToWait(0), tickerID(0) {}

Idler::Idler() :
state(false), idlerID(0) {}

LineLayout::LineLayout(int maxLineLength_) :
	lineStarts(0),
	lenLineStarts(0),
	lineNumber(-1),
	inCache(false),
	maxLineLength(-1),
	numCharsInLine(0),
	validity(llInvalid),
	xHighlightGuide(0),
	highlightColumn(0),
	selStart(0),
	selEnd(0),
	containsCaret(false),
	edgeColumn(0),
	chars(0),
	styles(0),
	styleBitsSet(0),
	indicators(0),
	positions(0),
	hsStart(0),
	hsEnd(0),
	widthLine(wrapWidthInfinite),
	lines(1) {
	Resize(maxLineLength_);
}

LineLayout::~LineLayout() {
	Free();
}

void LineLayout::Resize(int maxLineLength_) {
	if (maxLineLength_ > maxLineLength) {
		Free();
		chars = new char[maxLineLength_ + 1];
		styles = new unsigned char[maxLineLength_ + 1];
		indicators = new char[maxLineLength_ + 1];
		// Extra position allocated as sometimes the Windows
		// GetTextExtentExPoint API writes an extra element.
		positions = new int[maxLineLength_ + 1 + 1];
		maxLineLength = maxLineLength_;
	}
}

void LineLayout::Free() {
	delete []chars;
	chars = 0;
	delete []styles;
	styles = 0;
	delete []indicators;
	indicators = 0;
	delete []positions;
	positions = 0;
	delete []lineStarts;
	lineStarts = 0;
}

void LineLayout::Invalidate(validLevel validity_) {
	if (validity > validity_)
		validity = validity_;
}

void LineLayout::SetLineStart(int line, int start) {
	if ((line >= lenLineStarts) && (line != 0)) {
		int newMaxLines = line + 20;
		int *newLineStarts = new int[newMaxLines];
		if (!newLineStarts)
			return;
		for (int i = 0; i < newMaxLines; i++) {
			if (i < lenLineStarts)
				newLineStarts[i] = lineStarts[i];
			else
				newLineStarts[i] = 0;
		}
		delete []lineStarts;
		lineStarts = newLineStarts;
		lenLineStarts = newMaxLines;
	}
	lineStarts[line] = start;
}

void LineLayout::SetBracesHighlight(Range rangeLine, Position braces[],
                                    char bracesMatchStyle, int xHighlight) {
	if (rangeLine.ContainsCharacter(braces[0])) {
		int braceOffset = braces[0] - rangeLine.start;
		if (braceOffset < numCharsInLine) {
			bracePreviousStyles[0] = styles[braceOffset];
			styles[braceOffset] = bracesMatchStyle;
		}
	}
	if (rangeLine.ContainsCharacter(braces[1])) {
		int braceOffset = braces[1] - rangeLine.start;
		if (braceOffset < numCharsInLine) {
			bracePreviousStyles[1] = styles[braceOffset];
			styles[braceOffset] = bracesMatchStyle;
		}
	}
	if ((braces[0] >= rangeLine.start && braces[1] <= rangeLine.end) ||
	        (braces[1] >= rangeLine.start && braces[0] <= rangeLine.end)) {
		xHighlightGuide = xHighlight;
	}
}

void LineLayout::RestoreBracesHighlight(Range rangeLine, Position braces[]) {
	if (rangeLine.ContainsCharacter(braces[0])) {
		int braceOffset = braces[0] - rangeLine.start;
		if (braceOffset < numCharsInLine) {
			styles[braceOffset] = bracePreviousStyles[0];
		}
	}
	if (rangeLine.ContainsCharacter(braces[1])) {
		int braceOffset = braces[1] - rangeLine.start;
		if (braceOffset < numCharsInLine) {
			styles[braceOffset] = bracePreviousStyles[1];
		}
	}
	xHighlightGuide = 0;
}

LineLayoutCache::LineLayoutCache() :
	level(0), length(0), size(0), cache(0),
	allInvalidated(false), styleClock(-1), useCount(0) {
	Allocate(0);
}

LineLayoutCache::~LineLayoutCache() {
	Deallocate();
}

void LineLayoutCache::Allocate(int length_) {
	PLATFORM_ASSERT(cache == NULL);
	allInvalidated = false;
	length = length_;
	size = length;
	if (size > 1) {
		size = (size / 16 + 1) * 16;
	}
	if (size > 0) {
		cache = new LineLayout * [size];
	}
	for (int i = 0; i < size; i++)
		cache[i] = 0;
}

void LineLayoutCache::AllocateForLevel(int linesOnScreen, int linesInDoc) {
	PLATFORM_ASSERT(useCount == 0);
	int lengthForLevel = 0;
	if (level == llcCaret) {
		lengthForLevel = 1;
	} else if (level == llcPage) {
		lengthForLevel = linesOnScreen + 1;
	} else if (level == llcDocument) {
		lengthForLevel = linesInDoc;
	}
	if (lengthForLevel > size) {
		Deallocate();
		Allocate(lengthForLevel);
	} else {
		if (lengthForLevel < length) {
			for (int i = lengthForLevel; i < length; i++) {
				delete cache[i];
				cache[i] = 0;
			}
		}
		length = lengthForLevel;
	}
	PLATFORM_ASSERT(length == lengthForLevel);
	PLATFORM_ASSERT(cache != NULL || length == 0);
}

void LineLayoutCache::Deallocate() {
	PLATFORM_ASSERT(useCount == 0);
	for (int i = 0; i < length; i++)
		delete cache[i];
	delete []cache;
	cache = 0;
	length = 0;
	size = 0;
}

void LineLayoutCache::Invalidate(LineLayout::validLevel validity_) {
	if (cache && !allInvalidated) {
		for (int i = 0; i < length; i++) {
			if (cache[i]) {
				cache[i]->Invalidate(validity_);
			}
		}
		if (validity_ == LineLayout::llInvalid) {
			allInvalidated = true;
		}
	}
}

void LineLayoutCache::SetLevel(int level_) {
	allInvalidated = false;
	if ((level_ != -1) && (level != level_)) {
		level = level_;
		Deallocate();
	}
}

LineLayout *LineLayoutCache::Retrieve(int lineNumber, int lineCaret, int maxChars, int styleClock_,
                                      int linesOnScreen, int linesInDoc) {
	AllocateForLevel(linesOnScreen, linesInDoc);
	if (styleClock != styleClock_) {
		Invalidate(LineLayout::llCheckTextAndStyle);
		styleClock = styleClock_;
	}
	allInvalidated = false;
	int pos = -1;
	LineLayout *ret = 0;
	if (level == llcCaret) {
		pos = 0;
	} else if (level == llcPage) {
		if (lineNumber == lineCaret) {
			pos = 0;
		} else if (length > 1) {
			pos = 1 + (lineNumber % (length - 1));
		}
	} else if (level == llcDocument) {
		pos = lineNumber;
	}
	if (pos >= 0) {
		PLATFORM_ASSERT(useCount == 0);
		if (cache && (pos < length)) {
			if (cache[pos]) {
				if ((cache[pos]->lineNumber != lineNumber) ||
				        (cache[pos]->maxLineLength < maxChars)) {
					delete cache[pos];
					cache[pos] = 0;
				}
			}
			if (!cache[pos]) {
				cache[pos] = new LineLayout(maxChars);
			}
			if (cache[pos]) {
				cache[pos]->lineNumber = lineNumber;
				cache[pos]->inCache = true;
				ret = cache[pos];
				useCount++;
			}
		}
	}

	if (!ret) {
		ret = new LineLayout(maxChars);
		ret->lineNumber = lineNumber;
	}

	return ret;
}

void LineLayoutCache::Dispose(LineLayout *ll) {
	allInvalidated = false;
	if (ll) {
		if (!ll->inCache) {
			delete ll;
		} else {
			useCount--;
		}
	}
}

Editor::Editor() {
	ctrlID = 0;

	stylesValid = false;

	printMagnification = 0;
	printColourMode = SC_PRINT_NORMAL;
	printWrapState = eWrapWord;
	cursorMode = SC_CURSORNORMAL;
	controlCharSymbol = 0;	/* Draw the control characters */

	hasFocus = false;
	hideSelection = false;
	inOverstrike = false;
	errorStatus = 0;
	mouseDownCaptures = true;

	bufferedDraw = true;
	twoPhaseDraw = true;

	lastClickTime = 0;
	dwellDelay = SC_TIME_FOREVER;
	ticksToDwell = SC_TIME_FOREVER;
	dwelling = false;
	ptMouseLast.x = 0;
	ptMouseLast.y = 0;
	inDragDrop = false;
	dropWentOutside = false;
	posDrag = invalidPosition;
	posDrop = invalidPosition;
	selectionType = selChar;

	lastXChosen = 0;
	lineAnchor = 0;
	originalAnchorPos = 0;

	selType = selStream;
	moveExtendsSelection = false;
	xStartSelect = 0;
	xEndSelect = 0;
	primarySelection = true;

	caretXPolicy = CARET_SLOP | CARET_EVEN;
	caretXSlop = 50;

	caretYPolicy = CARET_EVEN;
	caretYSlop = 0;

	searchAnchor = 0;

	xOffset = 0;
	xCaretMargin = 50;
	horizontalScrollBarVisible = true;
	scrollWidth = 2000;
	verticalScrollBarVisible = true;
	endAtLastLine = true;
	caretSticky = false;

	pixmapLine = Surface::Allocate();
	pixmapSelMargin = Surface::Allocate();
	pixmapSelPattern = Surface::Allocate();
	pixmapIndentGuide = Surface::Allocate();
	pixmapIndentGuideHighlight = Surface::Allocate();

	currentPos = 0;
	anchor = 0;

	targetStart = 0;
	targetEnd = 0;
	searchFlags = 0;