+void BlackboxWindow::doWindowSnapping(int &dx, int &dy) {
+ // how much resistance to edges to provide
+ const int resistance_size = screen->getResistanceSize();
+
+ // how far away to snap
+ const int snap_distance = screen->getSnapThreshold();
+
+ // how to snap windows
+ const int snap_to_windows = screen->getWindowToWindowSnap();
+ const int snap_to_edges = screen->getWindowToEdgeSnap();
+ // the amount of space away from the edge to provide resistance/snap
+ const int snap_offset = screen->getSnapOffset();
+
+ // find the geomeetery where the moving window currently is
+ const Rect &moving = screen->doOpaqueMove() ? frame.rect : frame.changing;
+
+ // window corners
+ const int wleft = dx,
+ wright = dx + frame.rect.width() - 1,
+ wtop = dy,
+ wbottom = dy + frame.rect.height() - 1;
+
+ if (snap_to_windows) {
+ RectList rectlist;
+
+ Workspace *w = screen->getWorkspace(getWorkspaceNumber());
+ assert(w);
+
+ // add windows on the workspace to the rect list
+ const BlackboxWindowList& stack_list = w->getStackingList();
+ BlackboxWindowList::const_iterator st_it, st_end = stack_list.end();
+ for (st_it = stack_list.begin(); st_it != st_end; ++st_it)
+ if (*st_it != this) // don't snap to ourself
+ rectlist.push_back( (*st_it)->frameRect() );
+
+ // add the toolbar and the slit to the rect list.
+ // (only if they are not hidden)
+ Toolbar *tbar = screen->getToolbar();
+ Slit *slit = screen->getSlit();
+ Rect tbar_rect, slit_rect;
+ unsigned int bwidth = screen->getBorderWidth() * 2;
+
+ if (! (screen->doHideToolbar() || tbar->isHidden())) {
+ tbar_rect.setRect(tbar->getX(), tbar->getY(), tbar->getWidth() + bwidth,
+ tbar->getHeight() + bwidth);
+ rectlist.push_back(tbar_rect);
+ }
+
+ if (! slit->isHidden()) {
+ slit_rect.setRect(slit->getX(), slit->getY(), slit->getWidth() + bwidth,
+ slit->getHeight() + bwidth);
+ rectlist.push_back(slit_rect);
+ }
+
+ RectList::const_iterator it, end = rectlist.end();
+ for (it = rectlist.begin(); it != end; ++it) {
+ bool snapped = False;
+ const Rect &winrect = *it;
+ Rect offsetrect;
+ offsetrect.setCoords(winrect.left() - snap_offset,
+ winrect.top() - snap_offset,
+ winrect.right() + snap_offset,
+ winrect.bottom() + snap_offset);
+
+ if (snap_to_windows == BScreen::WindowResistance)
+ // if the window is already over top of this snap target, then
+ // resistance is futile, so just ignore it
+ if (winrect.intersects(moving))
+ continue;
+
+ int dleft, dright, dtop, dbottom;
+
+ // if the windows are in the same plane vertically
+ if (wtop >= (signed)(winrect.y() - frame.rect.height() + 1) &&
+ wtop < (signed)(winrect.y() + winrect.height() - 1)) {
+
+ if (snap_to_windows == BScreen::WindowResistance) {
+ dleft = wright - offsetrect.left();
+ dright = offsetrect.right() - wleft;
+
+ // snap left of other window?
+ if (dleft >= 0 && dleft < resistance_size &&
+ dleft < (wright - wleft)) {
+ dx = offsetrect.left() - frame.rect.width();
+ snapped = True;
+ }
+ // snap right of other window?
+ else if (dright >= 0 && dright < resistance_size &&
+ dright < (wright - wleft)) {
+ dx = offsetrect.right() + 1;
+ snapped = True;
+ }
+ } else { // BScreen::WindowSnap
+ dleft = abs(wright - offsetrect.left());
+ dright = abs(wleft - offsetrect.right());
+
+ // snap left of other window?
+ if (dleft < snap_distance && dleft <= dright) {
+ dx = offsetrect.left() - frame.rect.width();
+ snapped = True;
+ }
+ // snap right of other window?
+ else if (dright < snap_distance) {
+ dx = offsetrect.right() + 1;
+ snapped = True;
+ }
+ }
+
+ if (snapped) {
+ if (screen->getWindowCornerSnap()) {
+ // try corner-snap to its other sides
+ if (snap_to_windows == BScreen::WindowResistance) {
+ dtop = winrect.top() - wtop;
+ dbottom = wbottom - winrect.bottom();
+ if (dtop > 0 && dtop < resistance_size) {
+ // if we're already past the top edge, then don't provide
+ // resistance
+ if (moving.top() >= winrect.top())
+ dy = winrect.top();
+ } else if (dbottom > 0 && dbottom < resistance_size) {
+ // if we're already past the bottom edge, then don't provide
+ // resistance
+ if (moving.bottom() <= winrect.bottom())
+ dy = winrect.bottom() - frame.rect.height() + 1;
+ }
+ } else { // BScreen::WindowSnap
+ dtop = abs(wtop - winrect.top());
+ dbottom = abs(wbottom - winrect.bottom());
+ if (dtop < snap_distance && dtop <= dbottom)
+ dy = winrect.top();
+ else if (dbottom < snap_distance)
+ dy = winrect.bottom() - frame.rect.height() + 1;
+ }
+ }
+
+ continue;
+ }
+ }
+
+ // if the windows are on the same plane horizontally
+ if (wleft >= (signed)(winrect.x() - frame.rect.width() + 1) &&
+ wleft < (signed)(winrect.x() + winrect.width() - 1)) {
+
+ if (snap_to_windows == BScreen::WindowResistance) {
+ dtop = wbottom - offsetrect.top();
+ dbottom = offsetrect.bottom() - wtop;
+
+ // snap top of other window?
+ if (dtop >= 0 && dtop < resistance_size && dtop < (wbottom - wtop)) {
+ dy = offsetrect.top() - frame.rect.height();
+ snapped = True;
+ }
+ // snap bottom of other window?
+ else if (dbottom >= 0 && dbottom < resistance_size &&
+ dbottom < (wbottom - wtop)) {
+ dy = offsetrect.bottom() + 1;
+ snapped = True;
+ }
+ } else { // BScreen::WindowSnap
+ dtop = abs(wbottom - offsetrect.top());
+ dbottom = abs(wtop - offsetrect.bottom());
+
+ // snap top of other window?
+ if (dtop < snap_distance && dtop <= dbottom) {
+ dy = offsetrect.top() - frame.rect.height();
+ snapped = True;
+ }
+ // snap bottom of other window?
+ else if (dbottom < snap_distance) {
+ dy = offsetrect.bottom() + 1;
+ snapped = True;
+ }
+
+ }
+
+ if (snapped) {
+ if (screen->getWindowCornerSnap()) {
+ // try corner-snap to its other sides
+ if (snap_to_windows == BScreen::WindowResistance) {
+ dleft = winrect.left() - wleft;
+ dright = wright - winrect.right();
+ if (dleft > 0 && dleft < resistance_size) {
+ // if we're already past the left edge, then don't provide
+ // resistance
+ if (moving.left() >= winrect.left())
+ dx = winrect.left();
+ } else if (dright > 0 && dright < resistance_size) {
+ // if we're already past the right edge, then don't provide
+ // resistance
+ if (moving.right() <= winrect.right())
+ dx = winrect.right() - frame.rect.width() + 1;
+ }
+ } else { // BScreen::WindowSnap
+ dleft = abs(wleft - winrect.left());
+ dright = abs(wright - winrect.right());
+ if (dleft < snap_distance && dleft <= dright)
+ dx = winrect.left();
+ else if (dright < snap_distance)
+ dx = winrect.right() - frame.rect.width() + 1;
+ }
+ }
+
+ continue;
+ }
+ }
+ }
+ }
+
+ if (snap_to_edges) {
+ RectList rectlist;
+
+ // snap to the screen edges (and screen boundaries for xinerama)
+#ifdef XINERAMA
+ if (screen->isXineramaActive() && blackbox->doXineramaSnapping()) {
+ rectlist.insert(rectlist.begin(),
+ screen->getXineramaAreas().begin(),
+ screen->getXineramaAreas().end());
+ } else
+#endif // XINERAMA
+ rectlist.push_back(screen->getRect());
+
+ RectList::const_iterator it, end = rectlist.end();
+ for (it = rectlist.begin(); it != end; ++it) {
+ const Rect &srect = *it;
+ Rect offsetrect;
+ offsetrect.setCoords(srect.left() + snap_offset,
+ srect.top() + snap_offset,
+ srect.right() - snap_offset,
+ srect.bottom() - snap_offset);
+
+ if (snap_to_edges == BScreen::WindowResistance) {
+ // if we're not in the rectangle then don't snap to it.
+ if (! srect.contains(moving))
+ continue;
+ } else { // BScreen::WindowSnap
+ // if we're not in the rectangle then don't snap to it.
+ if (! srect.intersects(Rect(wleft, wtop, frame.rect.width(),
+ frame.rect.height())))
+ continue;
+ }
+
+ if (snap_to_edges == BScreen::WindowResistance) {
+ int dleft = offsetrect.left() - wleft,
+ dright = wright - offsetrect.right(),
+ dtop = offsetrect.top() - wtop,
+ dbottom = wbottom - offsetrect.bottom();
+
+ // snap left?
+ if (dleft > 0 && dleft < resistance_size)
+ dx = offsetrect.left();
+ // snap right?
+ else if (dright > 0 && dright < resistance_size)
+ dx = offsetrect.right() - frame.rect.width() + 1;
+
+ // snap top?
+ if (dtop > 0 && dtop < resistance_size)
+ dy = offsetrect.top();
+ // snap bottom?
+ else if (dbottom > 0 && dbottom < resistance_size)
+ dy = offsetrect.bottom() - frame.rect.height() + 1;
+ } else { // BScreen::WindowSnap
+ int dleft = abs(wleft - offsetrect.left()),
+ dright = abs(wright - offsetrect.right()),
+ dtop = abs(wtop - offsetrect.top()),
+ dbottom = abs(wbottom - offsetrect.bottom());
+
+ // snap left?
+ if (dleft < snap_distance && dleft <= dright)
+ dx = offsetrect.left();
+ // snap right?
+ else if (dright < snap_distance)
+ dx = offsetrect.right() - frame.rect.width() + 1;
+
+ // snap top?
+ if (dtop < snap_distance && dtop <= dbottom)
+ dy = offsetrect.top();
+ // snap bottom?
+ else if (dbottom < snap_distance)
+ dy = offsetrect.bottom() - frame.rect.height() + 1;
+ }
+ }
+ }
+}