java - Drag Multiple Objects Simultaneously -

how drag multiple selected objects , move around within frame?

the current implementation whenever user click on object, pressing shift key, each new object added multishape

however,i able move single selected object instead.

my code here:

public void mouseclicked(mouseevent clickevent) {              clickshape = null;             int x = clickevent.getx(); // x-coordinate of point mouse                                         // clicked             int y = clickevent.gety(); // y-coordinate of point              if (clickevent.isshiftdown()) {                 int top = shapes.size();                 (int = 0; < top; i++) {                     shape s = (shape) shapes.get(i);                     if (s.containspoint(x, y)) {                         s.setcolor(color.red);                         multishape.add(s);                     }                  }                  repaint();             }               }         } 

my moving object defined under abstract shape class follow:

void moveto(int x, int y) {             left += x;             top += y;         } 

mouseclick event:

public void mousepressed(mouseevent clickevent) {             if (dragshape != null) {                 return;             }              int x = clickevent.getx(); // x-coordinate of point             int y = clickevent.gety(); // y-coordinate of point             clickshape = null;             (int = shapes.size() - 1; >= 0; i--) { // check shapes                                                             // front                 shape s = (shape) shapes.get(i);                 if (s.containspoint(x, y)) {                      dragshape = s;                      prevdragx = x;                      prevdragy = y;                     clickshape = s;                     break;                 }             }             // continue here             if (clickshape == null) {                 return;             } else if (clickevent.ispopuptrigger()) {                 click.show(this, x - 10, y - 2);             }  else {                  dragshape = clickshape;                 prevdragx = x;                 prevdragy = y;             }          }          public void mousedragged(mouseevent clickevent) {             // user has moved mouse. move dragged shape same             // amount.             if (dragshape == null) {                 return;             }             int x = clickevent.getx();             int y = clickevent.gety();             if (dragshape != null) {             dragshape.moveto(x - prevdragx, y - prevdragy);             prevdragx = x;             prevdragy = y;             repaint(); // redraw canvas show shape in new position             }         }          public void mousereleased(mouseevent clickevent) {             // user has released mouse. move dragged shape, set             // shapebeingdragged null indicate dragging over.             if (dragshape == null) {                 return;             }             int x = clickevent.getx();             int y = clickevent.gety();             if (clickevent.ispopuptrigger()) {                 click.show(this, x - 10, y - 2);                 // } else {                 dragshape.moveto(x - prevdragx, y - prevdragy);                 if (dragshape.left >= getsize().width || dragshape.top >= getsize().height                         || dragshape.left + dragshape.width < 0 || dragshape.top + dragshape.height < 0) { // shape                     shapes.remove(dragshape); // remove shape list                 }                 repaint();             }             dragshape = null;         } 

you calling moveto 1 shape, called dragshape, last shape here

for (int = shapes.size() - 1; >= 0; i--) { // check shapes                                                         // front     shape s = (shape) shapes.get(i);     if (s.containspoint(x, y)) {          dragshape = s;          prevdragx = x;          prevdragy = y;          clickshape = s;          break;     } } 

instead of doing:

if (dragshape != null) { dragshape.moveto(x - prevdragx, y - prevdragy); 

do:

for (shape s : multishape)     s.moveto(x - prevdragx, y - prevdragy);