September 2013 - commonqt-devel - mailman3.common-lisp.net

[commonqt-devel] What is the recommended way to do background jobs in CommonQt?
by Rujia Liu 24 Sep '13

24 Sep '13

Hi! In my application, I need to download a big picture, when it is done, open a complex widget to show the picture (moving/zooming etc). I have options like threads in CL, QThread, QtConcurrent. What is the recommended way? Or maybe some of them just don't work? - Rujia

2 2

[commonqt-devel] Zoom in/out QGraphicsView centering on mouse position
by Rujia Liu 18 Sep '13

18 Sep '13

Hi! I want to implement a AutoCAD-like zoom in/out behavior and found this: http://www.qtcentre.org/threads/35738-How-to-zooming-like-in-AutoCAD-with-Q… I tried to use scale+centerOn (also in wheel event) but it doesn't work. It is scaled properly but does NOT center on the given point. Is there any workaround? - Rujia

2 4

[commonqt-devel] New QMouseEvent
by Rujia Liu 18 Sep '13

18 Sep '13

Hi! How to create a manual QMouseEvent? I wanna do this because I want to implement canvas dragging on midbutton. I'm referring to this code: http://levelfour.googlecode.com/svn/branches/dev/app/gui/GraphicsView.cpp It uses the following trick: if (event->button() == Qt::MidButton) { setDragMode(QGraphicsView::ScrollHandDrag); // create a new mouse event that simulates a click of the left button instead of the middle button QMouseEvent mouseEvent (event->type(), event->pos(), Qt::LeftButton, Qt::LeftButton, event->modifiers()); QGraphicsView::mousePressEvent(&mouseEvent); } That is, when midbutton is down, set the dragging mode and simulate a leftbutton press. The mouse release handler is similar and is omitted here. But when I tried in CommonQt I can only get "No applicable constructor QMouseEvent found for arguments..." Using "describe", I can see that the last two parameters should be QFlags<>, which is a template class. However there are no setXXX methods, so I cannot make changes to the current mouse event. Is there a workaround? - Rujia

2 2

[commonqt-devel] Comparing QButtons
by Rujia Liu 16 Sep '13

16 Sep '13

Hi! I've create a QMessageBox and tried to use clickedButton() to determine which button is clicked, like illustrated in QMessageBox::clickedButton ()'s document. My function: (defun yes-no-cancel-dialog (text informative-text yes-text no-text cancel-text) (with-objects ((message-box (#_new QMessageBox))) (#_setText message-box text) (#_setInformativeText message-box informative-text) (let ((yes-button (#_addButton message-box yes-text (#_QMessageBox::YesRole))) (no-button (#_addButton message-box no-text (#_QMessageBox::NoRole))) (cancel-button (#_addButton message-box cancel-text (#_QMessageBox::RejectRole))) (clicked-button)) (#_exec message-box) (setf clicked-button (#_clickedButton message-box)) (format t "clicked:~A~%" (#_clickedButton message-box)) (format t "clicked:~A~%" yes-button) (format t "clicked:~A~%" no-button) (format t "clicked:~A~%" cancel-button) (cond ((eq clicked-button yes-button) :yes) ((eq clicked-button no-button) :no) ((eq clicked-button cancel-button) :cancel) (t nil))))) When I click "yes" button, I can see something like: clicked:#<QPushButton 0x02003E18> clicked:#<QPushButton 0x02003E18> clicked:#<QPushButton 0x02004098> clicked:#<QPushButton 0x02004428> I tried eq, eql, equal and equalp, none of them return t when comparing clicked-button with yes-button. What can I do to compare two pointers? Thanks in advance. - Rujia

2 5

[commonqt-devel] Question abot CommonQt examples
by Rujia Liu 12 Sep '13

12 Sep '13

Dear all, I've just successfully installed CommonQt on Windows XP, and is able to run both qt-conv and tutorial-14. However, I have two questions. 1. In qt-conv example, if I run (main t) instead of (main), I got "Class not found: QApplication" error. But when i type (find-qclass "QApplication" t) in REPL, i got 1796. 2. in tutorial-14 example, I had to comment out two lines: ;(with-objects ((rect (#_new QRect -35 -35 70 70))) ; (#_drawPie painter rect 0 (* 90 16))) Otherwise I'll get: #<THREAD "main thread" RUNNING {23DA8A69}>: No applicable method drawPie found on #<QPainter 0x021705D0> with arguments (# <QRect 0x02174AB8> 0 ( * 90 16)) I'm using Qt 4.8.5 library for vs2008 and compiled smokegen/smokeqt with vs2008 express (without SP1) I used quicklisp to install commonqt yesterday, and is running qt-conv this way (ommited the output of the first 2 commands): E:\>sbcl * (require 'qt) * (load "qt-conv.lisp") * (qt-conv:main t) debugger invoked on a SIMPLE-ERROR in thread #<THREAD "main thread" RUNNING {23DA8A69}>: Class not found: QApplication Type HELP for debugger help, or (SB-EXT:EXIT) to exit from SBCL. restarts (invokable by number or by possibly-abbreviated name): 0: [ABORT] Exit debugger, returning to top level. (QT:FIND-QCLASS "QApplication" T) 0] 0 * (qt-conv:main) ;; then no error occurred. qt-conv will run perfectly Thanks in advance! - Rujia

2 10

[commonqt-devel] QGraphicsScene's mousemove event
by Rujia Liu 12 Sep '13

12 Sep '13

Hi! I found a strange thing. QGraphicsScene's mousemove event would not be triggered if the scene is empty. Actually if I only add a line item, mousemove event will not be triggered either. Only after a text is added, mousemove event is ok. It's no big deal because I could add an empty text to get everything work, but I'd like to know what's wrong (perhaps I've misunderstood something?) I can send you relavent codes if you need, but they're too big to post here. - Rujia

2 2

[commonqt-devel] Template class in CommonQt (e.g. QList)
by Rujia Liu 12 Sep '13

12 Sep '13

Hi! I'd like to create an item group for a QGraphicsScene with this function: QGraphicsItemGroup * QGraphicsScene::createItemGroup ( const QList<QGraphicsItem *> & items ) However, I don't know how to create a variable of type QList<QGraphicsItem*>. I even can't find the class: * (qt:qapropos "QList") ; No debug variables for current frame: using EVAL instead of EVAL-IN-FRAME. Class QListView Class QListWidget Class QListWidgetItem Method QListView::QListView [7272] Method QListView::QListView [7342] Method QListView::~QListView [7356] Method QListWidget::QListWidget [7364] Method QListWidget::QListWidget [7422] Method QListWidget::~QListWidget [7426] Method QListWidgetItem::QListWidgetItem [7427] Method QListWidgetItem::QListWidgetItem [7428] Method QListWidgetItem::QListWidgetItem [7429] Method QListWidgetItem::QListWidgetItem [7430] Method QListWidgetItem::QListWidgetItem [7472] Method QListWidgetItem::QListWidgetItem [7473] Method QListWidgetItem::QListWidgetItem [7474] Method QListWidgetItem::QListWidgetItem [7475] Method QListWidgetItem::QListWidgetItem [7476] Method QListWidgetItem::QListWidgetItem [7477] Method QListWidgetItem::~QListWidgetItem [7480] I tried to call canvas's items() and see what's inside. Then I see (#<QGraphicsItem 0x01FEB0B8> #<QGraphicsItem 0x01FEABB8>) That's the two items I created, before calling items(). So I see CommonQt does some magic to convert QList to a lisp list. Then I tried to pass nil (here I mean empty list, not false) to createItemGroup, but I got the following: The value NIL is not of type SYSTEM-AREA-POINTER. I think that's because nil is not like a "C pointer", but I know almost nothing about CFFI or other low-level stuffs, so I'm stuck now. - Rujia

2 2