xournalpp/src/control/tools/StrokeHandler.cpp

#include "StrokeHandler.h"

#include "control/layer/LayerController.h"
#include "gui/XournalView.h"
#include "gui/PageView.h"
#include "control/Control.h"
#include "undo/InsertUndoAction.h"
#include "control/shaperecognizer/ShapeRecognizerResult.h"
#include "undo/RecognizerUndoAction.h"

#include <config-features.h>

#include <gdk/gdk.h>
#include <cmath>

StrokeHandler::StrokeHandler(XournalView* xournal, XojPageView* redrawable, PageRef page)
 : InputHandler(xournal, redrawable, page),
   surfMask(NULL),
   crMask(NULL),
   reco(NULL)
{
	XOJ_INIT_TYPE(StrokeHandler);
}

StrokeHandler::~StrokeHandler()
{
	XOJ_CHECK_TYPE(StrokeHandler);

	destroySurface();
	delete reco;
	reco = NULL;

	XOJ_RELEASE_TYPE(StrokeHandler);
}

void StrokeHandler::draw(cairo_t* cr)
{
	XOJ_CHECK_TYPE(StrokeHandler);

	if (!stroke)
	{
		return;
	}

	view.applyColor(cr, stroke);

	if (stroke->getToolType() == STROKE_TOOL_HIGHLIGHTER) {
	  cairo_set_operator(cr, CAIRO_OPERATOR_MULTIPLY);
	}
	else {
	  cairo_set_operator(cr, CAIRO_OPERATOR_OVER);
	}

	cairo_mask_surface(cr, surfMask, 0, 0);
}

bool StrokeHandler::onMotionNotifyEvent(const PositionInputData& pos)
{
	XOJ_CHECK_TYPE(StrokeHandler);

	if (!stroke)
	{
		return false;
	}

	double zoom = xournal->getZoom();
	double x = pos.x / zoom;
	double y = pos.y / zoom;
	int pointCount = stroke->getPointCount();

	Point currentPoint(x, y);

	if (pointCount > 0)
	{
		if(!validMotion(currentPoint, stroke->getPoint(pointCount - 1)))
		{
			return true;
		}
	}

	if (Point::NO_PRESURE != pos.pressure && stroke->getToolType() == STROKE_TOOL_PEN)
	{
		stroke->setLastPressure(pos.pressure * stroke->getWidth());
	}

	stroke->addPoint(currentPoint);

	if ((stroke->getFill() != -1 || stroke->getLineStyle().hasDashes())
			&& !(stroke->getFill() != -1 && stroke->getToolType() == STROKE_TOOL_HIGHLIGHTER))
	{
		// Clear surface

		// for debugging purposes
		// cairo_set_source_rgba(crMask, 1, 0, 0, 1);
		cairo_set_source_rgba(crMask, 0, 0, 0, 0);
		cairo_rectangle(crMask, 0, 0, cairo_image_surface_get_width(surfMask), cairo_image_surface_get_height(surfMask));
		cairo_fill(crMask);

		view.drawStroke(crMask, stroke, 0, 1, true, true);
	}
	else
	{
		if (pointCount > 0)
		{
			Point prevPoint(stroke->getPoint(pointCount - 1));

			Stroke lastSegment;

			lastSegment.addPoint(prevPoint);
			lastSegment.addPoint(currentPoint);
			lastSegment.setWidth(stroke->getWidth());

			cairo_set_operator(crMask, CAIRO_OPERATOR_OVER);
			cairo_set_source_rgba(crMask, 1, 1, 1, 1);

			view.drawStroke(crMask, &lastSegment, 0, 1, false);
		}
	}

	const double w = stroke->getWidth();

	this->redrawable->repaintRect(stroke->getX() - w,
	                              stroke->getY() - w,
	                              stroke->getElementWidth() + 2*w,
	                              stroke->getElementHeight() + 2*w);

	return true;
}

void StrokeHandler::onButtonReleaseEvent(const PositionInputData& pos)
{
	XOJ_CHECK_TYPE(StrokeHandler);

	if (!stroke)
	{
		return;
	}

	// Backward compatibility and also easier to handle for me;-)
	// I cannot draw a line with one point, to draw a visible line I need two points,
	// twice the same Point is also OK
	if (stroke->getPointCount() == 1)
	{
		ArrayIterator<Point> it = stroke->pointIterator();
		if (it.hasNext())
		{
			stroke->addPoint(it.next());
		}
		// No pressure sensitivity
		stroke->clearPressure();
	}

	stroke->freeUnusedPointItems();

	Control* control = xournal->getControl();
	control->getLayerController()->ensureLayerExists(page);

	Layer* layer = page->getSelectedLayer();

	UndoRedoHandler* undo = control->getUndoRedoHandler();

	undo->addUndoAction(new InsertUndoAction(page, layer, stroke));

	ToolHandler* h = control->getToolHandler();

	if (h->getDrawingType() == DRAWING_TYPE_STROKE_RECOGNIZER)
	{
		if (reco == NULL)
		{
			reco = new ShapeRecognizer();
		}

		ShapeRecognizerResult* result = reco->recognizePatterns(stroke);

		if (result)
		{
			strokeRecognizerDetected(result, layer);

			// Full repaint is done anyway
			// So repaint don't need to be done here

			stroke = NULL;
			return;
		}
	}

	if (stroke->getFill() != -1 && stroke->getToolType() == STROKE_TOOL_HIGHLIGHTER)
	{
		// The stroke is not filled on drawing time
		// If the stroke has fill values, it needs to be re-rendered
		// else the fill will not be visible.

		view.drawStroke(crMask, stroke, 0, 1, true, true);
	}

	layer->addElement(stroke);
	page->fireElementChanged(stroke);

	//Manually force the rendering of the stroke, if no motion event occurred inbetween, that would rerender the page.
	if (stroke->getPointCount() == 2)
	{
		this->redrawable->rerenderElement(stroke);
	}

	stroke = NULL;

	return;
}

void StrokeHandler::strokeRecognizerDetected(ShapeRecognizerResult* result, Layer* layer)
{
	XOJ_CHECK_TYPE(StrokeHandler);

	Stroke* recognized = result->getRecognized();
	recognized->setWidth(stroke->hasPressure() ? stroke->getAvgPressure() : stroke->getWidth());

	RecognizerUndoAction* recognizerUndo = new RecognizerUndoAction(page, layer, stroke, recognized);

	UndoRedoHandler* undo = xournal->getControl()->getUndoRedoHandler();
	undo->addUndoAction(recognizerUndo);
	layer->addElement(result->getRecognized());

	Range range(recognized->getX(), recognized->getY());
	range.addPoint(recognized->getX() + recognized->getElementWidth(), recognized->getY() + recognized->getElementHeight());

	range.addPoint(stroke->getX(), stroke->getY());
	range.addPoint(stroke->getX() + stroke->getElementWidth(), stroke->getY() + stroke->getElementHeight());

	for (Stroke* s : *result->getSources())
	{
		layer->removeElement(s, false);

		recognizerUndo->addSourceElement(s);

		range.addPoint(s->getX(), s->getY());
		range.addPoint(s->getX() + s->getElementWidth(), s->getY() + s->getElementHeight());
	}

	page->fireRangeChanged(range);

	// delete the result object, this is not needed anymore, the stroke are not deleted with this
	delete result;
}

void StrokeHandler::onButtonPressEvent(const PositionInputData& pos)
{
	XOJ_CHECK_TYPE(StrokeHandler);

	destroySurface();

	double zoom = xournal->getZoom();
	PageRef page = redrawable->getPage();

	int dpiScaleFactor = xournal->getDpiScaleFactor();

	double width = page->getWidth() * zoom * dpiScaleFactor;
	double height = page->getHeight() * zoom * dpiScaleFactor;

	surfMask = cairo_image_surface_create(CAIRO_FORMAT_A8, width, height);

	crMask = cairo_create(surfMask);

	// for debugging purposes
	// cairo_set_source_rgba(crMask, 0, 0, 0, 1);
	cairo_set_source_rgba(crMask, 0, 0, 0, 0);
	cairo_rectangle(crMask, 0, 0, width, height);

	cairo_fill(crMask);

	cairo_scale(crMask, zoom * dpiScaleFactor, zoom * dpiScaleFactor);

	if (!stroke)
	{
		double x = pos.x / zoom;
		double y = pos.y / zoom;

		createStroke(Point(x, y));
	}
}

void StrokeHandler::destroySurface()
{
	XOJ_CHECK_TYPE(StrokeHandler);

	if (surfMask || crMask)
	{
		cairo_destroy(crMask);
		cairo_surface_destroy(surfMask);
		surfMask = NULL;
		crMask = NULL;
	}
}

void StrokeHandler::resetShapeRecognizer()
{
	XOJ_CHECK_TYPE(StrokeHandler);

	if (reco)
	{
		delete reco;
		reco = NULL;
	}
}