#ifdef HAVE_CONFIG_H

#include "config.h"

#endif

#include <glibmm/i18n.h>

#include "sp-item.h"

#include "desktop.h"

#include "message-context.h"

#include "message-stack.h"

#include "context-fns.h"

#include "snap.h"

#include "desktop-affine.h"

#include "event-context.h"

#include "sp-namedview.h"

#include "display/snap-indicator.h"

static const double midpt_1_goldenratio = (1 + goldenratio) / 2;

static const double midpt_goldenratio_2 = (goldenratio + 2) / 2;

bool Inkscape::have_viable_layer(SPDesktop *desktop, MessageContext *message)

{

SPItem const *layer = SP_ITEM(desktop->currentLayer());

if ( !layer || desktop->itemIsHidden(layer) ) {

message->flash(Inkscape::ERROR_MESSAGE,

_("<b>Current layer is hidden</b>. Unhide it to be able to draw on it."));

return false;

}

if ( !layer || layer->isLocked() ) {

message->flash(Inkscape::ERROR_MESSAGE,

_("<b>Current layer is locked</b>. Unlock it to be able to draw on it."));

return false;

}

return true;

}

bool Inkscape::have_viable_layer(SPDesktop *desktop, MessageStack *message)

{

SPItem const *layer = SP_ITEM(desktop->currentLayer());

if ( !layer || desktop->itemIsHidden(layer) ) {

message->flash(Inkscape::WARNING_MESSAGE,

_("<b>Current layer is hidden</b>. Unhide it to be able to draw on it."));

return false;

}

if ( !layer || layer->isLocked() ) {

message->flash(Inkscape::WARNING_MESSAGE,

_("<b>Current layer is locked</b>. Unlock it to be able to draw on it."));

return false;

}

return true;

}

Geom::Rect Inkscape::snap_rectangular_box(SPDesktop const *desktop, SPItem *item,

Geom::Point const &pt, Geom::Point const &center, int state)

{

Geom::Point p[2];

bool const shift = state & GDK_SHIFT_MASK;

bool const control = state & GDK_CONTROL_MASK;

SnapManager &m = desktop->namedview->snap_manager;

m.setup(desktop, false, item);

Inkscape::SnappedPoint snappoint;

if (control) {

/* Control is down: we are constrained to producing integer-ratio rectangles */

/* Vector from the centre of the box to the point we are dragging to */

Geom::Point delta = pt - center;

/* Round it so that we have an integer-ratio (or golden ratio) box */

if (fabs(delta[Geom::X]) > fabs(delta[Geom::Y]) && (delta[Geom::Y] != 0.0)) {

double ratio = delta[Geom::X] / delta[Geom::Y];

double ratioabs = fabs (ratio);

double sign = (ratio < 0 ? -1 : 1);

if (midpt_1_goldenratio < ratioabs && ratioabs < midpt_goldenratio_2) {

delta[Geom::X] = sign * goldenratio * delta[Geom::Y];

} else {

delta[Geom::X] = floor(ratio + 0.5) * delta[Geom::Y];

}

} else if (delta[Geom::X] != 0.0) {

double ratio = delta[Geom::Y] / delta[Geom::X];

double ratioabs = fabs (ratio);

double sign = (ratio < 0 ? -1 : 1);

if (midpt_1_goldenratio < ratioabs && ratioabs < midpt_goldenratio_2) {

delta[Geom::Y] = sign * goldenratio * delta[Geom::X];

} else {

delta[Geom::Y] = floor(delta[Geom::Y] / delta[Geom::X] + 0.5) * delta[Geom::X];

}

}

/* p[1] is the dragged point with the integer-ratio constraint */

p[1] = center + delta;

if (shift) {

/* Shift is down, so our origin is the centre point rather than the corner

/* p[0] is the opposite corner of our box */

p[0] = center - delta;

Inkscape::SnappedPoint s[2];

/* Try to snap p[0] (the opposite corner) along the constraint vector */

s[0] = m.constrainedSnap(Inkscape::SnapPreferences::SNAPPOINT_NODE, to_2geom(p[0]),

Inkscape::Snapper::ConstraintLine(p[0] - p[1]));

/* Try to snap p[1] (the dragged corner) along the constraint vector */

s[1] = m.constrainedSnap(Inkscape::SnapPreferences::SNAPPOINT_NODE, to_2geom(p[1]),

Inkscape::Snapper::ConstraintLine(p[1] - p[0]));

/* Choose the best snap and update points accordingly */

if (s[0].getSnapDistance() < s[1].getSnapDistance()) {

if (s[0].getSnapped()) {

p[0] = s[0].getPoint();

p[1] = 2 * center - s[0].getPoint();

snappoint = s[0];

}

} else {

if (s[1].getSnapped()) {

p[0] = 2 * center - s[1].getPoint();

p[1] = s[1].getPoint();

snappoint = s[1];

}

}

} else {

/* Our origin is the opposite corner. Snap the drag point along the constraint vector */

p[0] = center;

snappoint = m.constrainedSnap(Inkscape::SnapPreferences::SNAPPOINT_NODE, to_2geom(p[1]),

Inkscape::Snapper::ConstraintLine(p[1] - p[0]));

if (snappoint.getSnapped()) {

p[1] = snappoint.getPoint();

}

}

} else if (shift) {

/* Shift is down, so our origin is the centre point rather than the corner point;

p[1] = pt;

p[0] = 2 * center - p[1];

Inkscape::SnappedPoint s[2];

s[0] = m.freeSnap(Inkscape::SnapPreferences::SNAPPOINT_NODE, to_2geom(p[0]));

s[1] = m.freeSnap(Inkscape::SnapPreferences::SNAPPOINT_NODE, to_2geom(p[1]));

if (s[0].getSnapDistance() < s[1].getSnapDistance()) {

if (s[0].getSnapped()) {

p[0] = s[0].getPoint();

p[1] = 2 * center - s[0].getPoint();

snappoint = s[0];

}

} else {

if (s[1].getSnapped()) {

p[0] = 2 * center - s[1].getPoint();

p[1] = s[1].getPoint();

snappoint = s[1];

}

}

} else {

/* There's no constraint on the corner point, so just snap it to anything */

p[0] = center;

p[1] = pt;

snappoint = m.freeSnap(Inkscape::SnapPreferences::SNAPPOINT_NODE, to_2geom(pt));

if (snappoint.getSnapped()) {

p[1] = snappoint.getPoint();

}

}

if (snappoint.getSnapped()) {

desktop->snapindicator->set_new_snappoint(snappoint);

}

p[0] = sp_desktop_dt2root_xy_point(desktop, p[0]);

p[1] = sp_desktop_dt2root_xy_point(desktop, p[1]);

return Geom::Rect(Geom::Point(MIN(p[0][Geom::X], p[1][Geom::X]), MIN(p[0][Geom::Y], p[1][Geom::Y])),

Geom::Point(MAX(p[0][Geom::X], p[1][Geom::X]), MAX(p[0][Geom::Y], p[1][Geom::Y])));

}

Geom::Point Inkscape::setup_for_drag_start(SPDesktop *desktop, SPEventContext* ec, GdkEvent *ev)

{

ec->xp = static_cast<gint>(ev->button.x);

ec->yp = static_cast<gint>(ev->button.y);

ec->within_tolerance = true;

Geom::Point const p(ev->button.x, ev->button.y);

ec->item_to_select = sp_event_context_find_item(desktop, p, ev->button.state & GDK_MOD1_MASK, TRUE);

return ec->desktop->w2d(p);

}