The processEvents / screen update recursion bug fix.

git-svn-id: svn://svn.lyx.org/lyx/lyx-devel/trunk@9931 a592a061-630c-0410-9148-cb99ea01b6c8

diff --git a/src/BufferView_pimpl.C b/src/BufferView_pimpl.C
index eb6582816f73c06cfc4ae09894c0d2ca29275460..ce12c3d10af9544c08731902df47a92d4d9a9dcd 100644 (file)
--- a/src/BufferView_pimpl.C
+++ b/src/BufferView_pimpl.C
@@ -617,12 +617,20 @@ void BufferView::Pimpl::update(bool fitcursor, bool forceupdate)
        if (buffer_) {
                // Update macro store
                buffer_->buildMacros();
-               // First drawing step
 
                CoordCache backup;
                std::swap(theCoords, backup);
+               
+               // This call disallows cursor blink to call
+               // processEvents. It is necessary to prevent screen
+               // redraw being called recursively.
+               screen().unAllowSync();
+               // This, together with doneUpdating(), verifies (using
+               // asserts) that screen redraw is not called from 
+               // within itself.
                theCoords.startUpdating();
 
+               // First drawing step
                ViewMetricsInfo vi = metrics();
 
                if (fitcursor && fitCursor()) {
@@ -633,7 +641,8 @@ void BufferView::Pimpl::update(bool fitcursor, bool forceupdate)
                        // Second drawing step
                        screen().redraw(*bv_, vi);
                } else {
-                       // Abort updating of the coord cache - just restore the old one
+                       // Abort updating of the coord
+                       // cache - just restore the old one
                        std::swap(theCoords, backup);
                }
        } else

diff --git a/src/ChangeLog b/src/ChangeLog
index c878219061746bea7fa8252e309bdcdd8e35ebf5..c7463cf8196fc81ef67a3fa7f1519532d0b3ac08 100644 (file)
--- a/src/ChangeLog
+++ b/src/ChangeLog
@@ -1,3 +1,8 @@
+2005-05-11  Martin Vermeer  <martin.vermeer@hut.fi>
+
+       * BufferView_pimpl.C (update): fix processEvents -caused update
+       recursion bug
+
 2005-05-09  Georg Baum  <Georg.Baum@post.rwth-aachen.de>
 
        * cursor.h (undispatched, noUpdate): add comments from André

diff --git a/src/frontends/ChangeLog b/src/frontends/ChangeLog
index e7aed9bff54bd772bab055a1563669872461f6f0..0ed23a44bff5378d8e8cb4b16b1baccdd4735e3a 100644 (file)
--- a/src/frontends/ChangeLog
+++ b/src/frontends/ChangeLog
@@ -1,3 +1,8 @@
+2005-05-11  Martin Vermeer  <martin.vermeer@hut.fi>
+
+       * screen.[hC]: fix processEvents -caused screen update recursion
+       bug
+
 2005-04-25  Angus Leeming  <leeming@lyx.org>
 
        * LyXView.C:

diff --git a/src/frontends/qt2/ChangeLog b/src/frontends/qt2/ChangeLog
index ede22cdaa21e53aff1487d3b687b8248fee7beac..c5f851f7e813e89336ce722f35de905c0f8e2676 100644 (file)
--- a/src/frontends/qt2/ChangeLog
+++ b/src/frontends/qt2/ChangeLog
@@ -1,3 +1,11 @@
+2005-05-11  Martin Vermeer  <martin.vermeer@hut.fi>
+
+       * lyx_gui.C (sync_events):
+       * QDialogView.h (update, build):
+       * QLPopupMenu.C (fire):
+       * QMathDialog.C (resizeEvent, showingPanel): fix processEvent
+       -caused update recursion bug
+
 2005-05-06  Michael Schmitt  <michael.schmitt@teststep.org>
 
        * ui/*.ui: remove captions: they are unused and pollute the po

diff --git a/src/frontends/qt2/QDialogView.h b/src/frontends/qt2/QDialogView.h
index 061c8537b392534947bed703296fd3609cc8d17c..41baaa5f22749f392db2044a004602894bdb8980 100644 (file)
--- a/src/frontends/qt2/QDialogView.h
+++ b/src/frontends/qt2/QDialogView.h
@@ -126,10 +126,8 @@ void QView<GUIDialog>::update()
 
        // protect the BC from unwarranted state transitions
 
-       qApp->processEvents();
        updating_ = true;
        update_contents();
-       qApp->processEvents();
        updating_ = false;
 
        form()->setUpdatesEnabled(true);
@@ -142,10 +140,8 @@ void QView<GUIDialog>::build()
 {
        // protect the BC from unwarranted state transitions
 
-       qApp->processEvents();
        updating_ = true;
        build_dialog();
-       qApp->processEvents();
        updating_ = false;
 }
 

diff --git a/src/frontends/qt2/QLPopupMenu.C b/src/frontends/qt2/QLPopupMenu.C
index 1f1ba57aa6726c268e93b5a22a1a5ee82e99f3f9..677a4fa6a3233a7643f71dd49fefe9057b7845ee 100644 (file)
--- a/src/frontends/qt2/QLPopupMenu.C
+++ b/src/frontends/qt2/QLPopupMenu.C
@@ -88,7 +88,6 @@ QLPopupMenu::QLPopupMenu(QLMenubar * owner,
 
 void QLPopupMenu::fire(int index)
 {
-       qApp->processEvents();
 #ifdef Q_WS_MACX
        if (index >= indexOffset) {
                MenuItem mi = owner_->backend().getMenu("LyX")[index - indexOffset];

diff --git a/src/frontends/qt2/QMathDialog.C b/src/frontends/qt2/QMathDialog.C
index 0c43674accbb413f0f1da1e5abc8456e6123c0f9..59ee731754d101a366df4e0965f7198df946aaa8 100644 (file)
--- a/src/frontends/qt2/QMathDialog.C
+++ b/src/frontends/qt2/QMathDialog.C
@@ -52,8 +52,7 @@ protected:
                        return;
 
                w_->resize(viewport()->width(), w_->height());
-               // force the resize to get accurate scrollbars
-               qApp->processEvents();
+               // force the resize to get accurate scrollbar
                resizeContents(w_->width(), w_->height());
        }
 private:
@@ -156,9 +155,6 @@ void QMathDialog::showingPanel(int num)
 
        addPanel(num);
 
-       // Qt needs to catch up. Dunno why.
-       qApp->processEvents();
-
        panel_initialised[num] = true;
 }
 

diff --git a/src/frontends/qt2/lyx_gui.C b/src/frontends/qt2/lyx_gui.C
index f5230da5570d72ea3dd4dde4ceee1490b6e2e2b7..7b47712385219c7156849fb748d6eb6b71b54d17 100644 (file)
--- a/src/frontends/qt2/lyx_gui.C
+++ b/src/frontends/qt2/lyx_gui.C
@@ -252,6 +252,10 @@ void start(string const & batch, vector<string> const & files)
 
 void sync_events()
 {
+       // This is the ONLY place where processEvents may be called.
+       // During screen update/ redraw, this method is disabled to 
+       // prevent keyboard events being handed to the LyX core, where
+       // they could cause re-entrant calls to screen update.
        qApp->processEvents();
 }
 

diff --git a/src/frontends/screen.C b/src/frontends/screen.C
index 6308730a2024b786afcee8824d1fa9721c2683fc..537a13a8aa67da716962320c9def9e0639fcff86 100644 (file)
--- a/src/frontends/screen.C
+++ b/src/frontends/screen.C
@@ -122,7 +122,7 @@ SplashScreen::SplashScreen()
 
 
 LyXScreen::LyXScreen()
-       : greyed_out_(true), cursor_visible_(false)
+       : greyed_out_(true), cursor_visible_(false), sync_allowed_(true)
 {
        // Start loading the pixmap as soon as possible
        if (lyxrc.show_banner) {
@@ -147,15 +147,19 @@ void LyXScreen::checkAndGreyOut()
 
 void LyXScreen::showCursor(BufferView & bv)
 {
-       // You are not expected to understand this. This forces Qt
-       // (the problem case) to deal with its event queue. This is
-       // necessary when holding down a key such as 'page down' or
-       // just typing: without this processing of the event queue,
-       // the cursor gets ahead of itself without a selection or
-       // workarea redraw having a chance to keep up. If you think
-       // you can remove this, try selecting text with the mouse
-       // in Qt, or holding Page Down on the User's Guide.
-       lyx_gui::sync_events();
+       // This code is currently meaningful only for the Qt frontend.
+       // This is the place (like below in hideCursor) where
+       // processEvents is being called, and things like keystrokes and
+       // mouse clicks are being handed to the LyX core, once every 
+       // cursor blink. 
+       // THERE IS NOT SUPPOSED TO BE ANY OTHER CALL TO processEvents 
+       // ANYWHERE ELSE.
+       // in BufferView::Pimpl::update() and here, the sync_allowed_
+       // guard is set/cleared which is used here to prevent recursive
+       // calls to screen update. startUpdating() and doneUpdating() in
+       // coordcache again contain asserts to detect such recursion.
+       if (sync_allowed_)
+               lyx_gui::sync_events();
 
        if (cursor_visible_)
                return;
@@ -202,6 +206,9 @@ void LyXScreen::showCursor(BufferView & bv)
 
 void LyXScreen::hideCursor()
 {
+       if (sync_allowed_)
+               lyx_gui::sync_events();
+
        if (!cursor_visible_)
                return;
 
@@ -223,13 +230,12 @@ void LyXScreen::redraw(BufferView & bv, ViewMetricsInfo const & vi)
 {
        greyed_out_ = false;
        workarea().getPainter().start();
-       hideCursor();
        paintText(bv, vi);
        lyxerr[Debug::DEBUG] << "Redraw screen" << endl;
        expose(0, 0, workarea().workWidth(), workarea().workHeight());
        workarea().getPainter().end();
        theCoords.doneUpdating();
-       showCursor(bv);
+       sync_allowed_ = true;
 }
 
 

diff --git a/src/frontends/screen.h b/src/frontends/screen.h
index e229864525d47d123314f42c31de7bc67a70077a..fd3f6e78a39362a564e228b8f94198cc466b5445 100644 (file)
--- a/src/frontends/screen.h
+++ b/src/frontends/screen.h
@@ -54,6 +54,9 @@ public:
        /// toggle the cursor's visibility
        void toggleCursor(BufferView & bv);
 
+       ///
+       void unAllowSync() { sync_allowed_ = false; };
+
 protected:
        /// cause the display of the given area of the work area
        virtual void expose(int x, int y, int w, int h) = 0;
@@ -86,6 +89,9 @@ private:
 
        /// is the cursor currently displayed
        bool cursor_visible_;
+
+       ///
+       bool sync_allowed_;
 };
 
 #endif // SCREEN_H