# TreeWidgetItem problem **URL:** \ **Category:** Ruby\ **Created:** [May 17, 2007, 11:51am UTC](https://www.ruby-forum.com/t/treewidgetitem-problem/104378 "2007-05-17T11:51:18Z")\ **Posts on this page:** 6\ **Page:** 1
**Author:** ![miquel](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/m/e495f1/32.png) [@miquel](https://www.ruby-forum.com/u/miquel)\ **Post date:** [May 17, 2007, 11:51am UTC](https://www.ruby-forum.com/t/treewidgetitem-problem/104378/1 "2007-05-17T11:51:18Z")
Hi there I’m trying to code a Tree using ruby qt bindings (Qt v4.2.0 using aboutQt() info). This is my code. @tree = Qt::TreeWidget.new(self) self.setCentralWidget(@tree) @rootItem = Qt::TreeWidgetItem.new(@tree) @rootItem.setText(0, “Root”) 0.upto(10) do |index| item = Qt::TreeWidgetItem.new(@rootItem) item.setText(0, “Node#{index}”) end The problem is in ‘item = Qt::TreeWidgetItem.new(@rootItem)’, system tells me: unresolved constructor call Qt::TreeWidgetItem (ArgumentError) and reading Qt documentation there are two constructors allowed: QTreeWidgetItem ( QTreeWidget \* parent, int type = Type ) QTreeWidgetItem ( QTreeWidgetItem \* parent, int type = Type ) The first one is used in the @rootNode object creation and the second one is the one which produces this message. Can anybody help me? Thanks in advance Best regards Miquel ---
**Author:** ![miquel](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/m/e495f1/32.png) [@miquel](https://www.ruby-forum.com/u/miquel)\ **Post date:** [May 17, 2007, 12:02pm UTC](https://www.ruby-forum.com/t/treewidgetitem-problem/104378/2 "2007-05-17T12:02:20Z")
Alle giovedì 17 maggio 2007, Miquel ha scritto: > @rootItem = Qt::TreeWidgetItem.new(@tree) > unresolved constructor call Qt::TreeWidgetItem (ArgumentError) > > Thanks in advance > > Best regards > > Miquel It seems that you need to specify also the optional parameter. If you substitute the line item = Qt::TreeWidgetItem.new(@rootItem) with item = Qt::TreeWidgetItem.new(@rootItem, Qt::TreeWidgetItem::Type) it should work (at least, it does on my system, with qt 4.2.3). I hope this helps Stefano ---
**Author:** ![miquel](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/m/e495f1/32.png) [@miquel](https://www.ruby-forum.com/u/miquel)\ **Post date:** [May 17, 2007, 12:14pm UTC](https://www.ruby-forum.com/t/treewidgetitem-problem/104378/3 "2007-05-17T12:14:24Z")
En/na Stefano C. ha escrit: > > self.setCentralWidget(@tree) > > tells me: > > It seems that you need to specify also the optional parameter. If you Hey, it is 😃 !!! but…Why isn’t it necessary in the root node creation (the constructor have the same optional parameter)? Thanks ``` Miquel ``` ---
**Author:** ![miquel](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/m/e495f1/32.png) [@miquel](https://www.ruby-forum.com/u/miquel)\ **Post date:** [May 17, 2007, 1:01pm UTC](https://www.ruby-forum.com/t/treewidgetitem-problem/104378/4 "2007-05-17T13:01:04Z")
Alle giovedì 17 maggio 2007, Miquel ha scritto: > > > self.setCentralWidget(@tree) > > > tells me: > > > > substitute the line > > creation (the constructor have the same optional parameter)? > > Thanks > > ``` > Miquel > > ``` Looking at the Korudum forum ([http://rubyforge.org/forum/forum.php?forum\_id=723](http://rubyforge.org/forum/forum.php?forum_id=723)), it seems there are some situations in which QtRuby fails to correctly resolve overloaded methods. In this case, the constructor which takes a Qt::ListWidget is resolved correctly, the other isn’t. A similar situation occurred me using Qt::MessageBox.question. Although the documentation says the buttons and defaultButton parameters are optional, the method call failed in ruby unless they were both specified. Another example is mentioned on this thread of the Korundum forum: [http://rubyforge.org/forum/message.php?msg\_id=15576](http://rubyforge.org/forum/message.php?msg_id=15576) Stefano ---
**Author:** ![miquel](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/m/e495f1/32.png) [@miquel](https://www.ruby-forum.com/u/miquel)\ **Post date:** [May 17, 2007, 5:56pm UTC](https://www.ruby-forum.com/t/treewidgetitem-problem/104378/5 "2007-05-17T17:56:02Z")
On May 17, 11:01 am, Stefano C. [removed\_email\_address@domain.invalid](mailto:removed_email_address@domain.invalid) wrote: > > The first one is used in the @rootNode object creation and the second > > It seems that you need to specify also the optional parameter. If you > > substitute the line > > item = Qt::TreeWidgetItem.new(@rootItem) > > with > > item = Qt::TreeWidgetItem.new(@rootItem, Qt::TreeWidgetItem::Type) > > it should work (at least, it does on my system, with qt 4.2.3). > > I’ve found out what the problem is, and it’s already fixed in the kde > > svn version of QtRuby. Here is the entry from the ChangeLog: 2006-12-16 Richard Dale [rdale@xxxx](mailto:rdale@xxxx) - There is no way to distinguish between the two constructors: QTreeWidgetItem (const QTreeWidgetItem & other) QTreeWidgetItem (QTreeWidgetItem \* parent, const QStringList & strings, int type = Type) when the latter has a single argument. So force the second variant to be called – Richard ---
**Author:** ![miquel](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/m/e495f1/32.png) [@miquel](https://www.ruby-forum.com/u/miquel)\ **Post date:** [May 17, 2007, 1:08pm UTC](https://www.ruby-forum.com/t/treewidgetitem-problem/104378/6 "2007-05-17T13:08:05Z")
En/na Stefano C. ha escrit: > > > > ``` > > > > item.setText(0, "Node#{index}") > > > > > > > > ``` > > > > > > > > QTreeWidgetItem ( QTreeWidgetItem \* parent, int type = Type ) > > Stefano Ok, I have reported this issue to the KDE bindings list and Richard Dale is asking me some questions. If you are interested in final conclusions I’ll post here 😃 Thanks for all Best regards ``` Miquel ```