BlockStack MergeStacks(IBlock b1, IBlock b2)
{
BlockStack ret = new BlockStack();
if ((b1 is BlockStack))
{
BlockStack bs1 = b1 as BlockStack;
ret.AddRange(bs1);
}
else
{
// We need to remove b1 from its parent before adding it to the newly merged stack
// otherwise consider such a scenario:
// 1- We drag a stack block into an existing stackBlock in a C block
// 2- 'b1' is the existing stackBlock, it is not added to ret, but is still an arg of the C block
// 3- after merge is called, we'll try to set ret as the arg of the C block; the C will try
// to remove the old arg (b1)...but it doesn't have C as a parent! exception thrown
b1.ParentRelationship.Detach(this);
ret.Add(b1);
}
if ((b2 is BlockStack))
{
BlockStack bs2 = b2 as BlockStack;
ret.AddRange(bs2);
}
else
{
b2.ParentRelationship.Detach(this);
ret.Add(b2);
}
return(ret);
}
BlockStack makeSampleBlockStack()
{
InvokationBlock b1 = makeInvokationBlock("move % steps",
new DataType[] { DataType.Number },
DataType.Script,
new IBlock[] { new TextBlock("") });
InvokationBlock b2 = makeInvokationBlock("turn % degrees right",
new DataType[] { DataType.Number },
DataType.Script,
new IBlock[] { new TextBlock("") });
BlockStack stack = new BlockStack();
stack.AddRange(new IBlock[] { b1, b2 });
return(stack);
}
