971         // An "INFO: index exceeds maxCellCount" message should print out.
 972         flow.setCreateCell(p -> new CellStub(flow) {
 973             @Override
 974             protected double computeMaxHeight(double width) { return 0; }
 975             @Override
 976             protected double computePrefHeight(double width) { return 0; }
 977             @Override
 978             protected double computeMinHeight(double width) { return 0; }
 979 
 980         });
 981         flow.setCellCount(10);
 982         flow.setViewportLength(100);
 983         flow.addLeadingCells(1, 0);
 984         flow.sheetChildren.addListener((InvalidationListener) (o) -> {
 985             int count = ((List) o).size();
 986             assertTrue(Integer.toString(count), count <= 100);
 987         });
 988         flow.addTrailingCells(true);
 989     }
 990 




























































 991 }
 992 
 993 class CellStub extends IndexedCell {
 994     String s;
 995     VirtualFlow flow;
 996 
 997     public CellStub(VirtualFlow flow) { init(flow); }
 998     public CellStub(VirtualFlow flow, String s) { init(flow); this.s = s; }
 999     
1000     private void init(VirtualFlow flow) {
1001         this.flow = flow;
1002         setSkin(new SkinStub<CellStub>(this));
1003         updateItem(this, false);
1004     }
1005 
1006     @Override
1007     public void updateIndex(int i) {
1008         super.updateIndex(i);
1009         
1010         s = "Item " + getIndex();

 971         // An "INFO: index exceeds maxCellCount" message should print out.
 972         flow.setCreateCell(p -> new CellStub(flow) {
 973             @Override
 974             protected double computeMaxHeight(double width) { return 0; }
 975             @Override
 976             protected double computePrefHeight(double width) { return 0; }
 977             @Override
 978             protected double computeMinHeight(double width) { return 0; }
 979 
 980         });
 981         flow.setCellCount(10);
 982         flow.setViewportLength(100);
 983         flow.addLeadingCells(1, 0);
 984         flow.sheetChildren.addListener((InvalidationListener) (o) -> {
 985             int count = ((List) o).size();
 986             assertTrue(Integer.toString(count), count <= 100);
 987         });
 988         flow.addTrailingCells(true);
 989     }
 990 
 991     private int rt36556_instanceCount;
 992     @Test
 993     public void test_rt36556() {
 994         rt36556_instanceCount = 0;
 995         flow = new VirtualFlow();
 996         flow.setVertical(true);
 997         flow.setCreateCell(p -> {
 998             rt36556_instanceCount++;
 999             return new CellStub(flow);
1000         });
1001         flow.setCellCount(100);
1002         flow.resize(300, 300);
1003         pulse();
1004         final int cellCountAtStart = rt36556_instanceCount;
1005         flow.adjustPixels(10000);
1006         pulse();
1007         assertEquals(cellCountAtStart, rt36556_instanceCount);
1008         assertNull(flow.getVisibleCell(0));
1009         assertMinimalNumberOfCellsAreUsed(flow);
1010     }
1011 
1012     @Test
1013     public void test_rt36556_scrollto() {
1014         rt36556_instanceCount = 0;
1015         flow = new VirtualFlow();
1016         flow.setVertical(true);
1017         flow.setCreateCell(p -> {
1018             rt36556_instanceCount++;
1019             return new CellStub(flow);
1020         });
1021         flow.setCellCount(100);
1022         flow.resize(300, 300);
1023         pulse();
1024         final int cellCountAtStart = rt36556_instanceCount;
1025         flow.scrollTo(80);
1026         pulse();
1027         assertEquals(cellCountAtStart, rt36556_instanceCount);
1028         assertNull(flow.getVisibleCell(0));
1029         assertMinimalNumberOfCellsAreUsed(flow);
1030     }
1031     
1032     @Test
1033     public void test_RT39035() {
1034         flow.adjustPixels(250);
1035         pulse();
1036         flow.adjustPixels(500);
1037         pulse();
1038         assertTrue(flow.getPosition() < 1.0);
1039         assertMinimalNumberOfCellsAreUsed(flow);
1040     }
1041 
1042     @Test
1043     public void test_RT37421() {
1044         flow.setPosition(0.98);
1045         pulse();
1046         flow.adjustPixels(100);
1047         pulse();
1048         assertEquals(1.0, flow.getPosition(), 0.0);
1049         assertMinimalNumberOfCellsAreUsed(flow);
1050     }
1051 }
1052 
1053 class CellStub extends IndexedCell {
1054     String s;
1055     VirtualFlow flow;
1056 
1057     public CellStub(VirtualFlow flow) { init(flow); }
1058     public CellStub(VirtualFlow flow, String s) { init(flow); this.s = s; }
1059     
1060     private void init(VirtualFlow flow) {
1061         this.flow = flow;
1062         setSkin(new SkinStub<CellStub>(this));
1063         updateItem(this, false);
1064     }
1065 
1066     @Override
1067     public void updateIndex(int i) {
1068         super.updateIndex(i);
1069         
1070         s = "Item " + getIndex();