Install a new compressor

A brand new event compressor based on Kuba Ober's cleverly simple
solution: <https://stackoverflow.com/a/21006207>.

Fix #9362, #9461, #9933: Lyx suddenly gets keyboard keys wrong, and
deadlocks

Fix #9790: LyX should perform key event compression (for improving the
remote X connections one would also need to implement
Qt::WA_KeyCompression)

Fix #10516: slowness on repeated arrow keys with IBus and Qt5

Patch pulled from
https://github.com/gadmm/lyx-unstable/commit/bf5a1efb0db5bfc2b

Signed-off-by: Juergen Spitzmueller <spitz@lyx.org>

diff --git a/src/frontends/qt4/GuiWorkArea.cpp b/src/frontends/qt4/GuiWorkArea.cpp
index 3d169d02ee134a612c8303fc95b49f0068bae242..be1b4d4dcc5f8ac561fe61dd8fde3235d850f22f 100644 (file)
--- a/src/frontends/qt4/GuiWorkArea.cpp
+++ b/src/frontends/qt4/GuiWorkArea.cpp
@@ -276,6 +276,7 @@ GuiWorkArea::GuiWorkArea(QWidget * /* w */)
 GuiWorkArea::GuiWorkArea(Buffer & buffer, GuiView & gv)
 : d(new Private(this))
 {
+       new CompressorProxy(this); // not a leak
        setGuiView(gv);
        buffer.params().display_pixel_ratio = theGuiApp()->pixelRatio();
        setBuffer(buffer);
@@ -1033,6 +1034,37 @@ void GuiWorkArea::generateSyntheticMouseEvent()
 }
 
 
+// CompressorProxy adapted from Kuba Ober https://stackoverflow.com/a/21006207
+CompressorProxy::CompressorProxy(GuiWorkArea * wa) : QObject(wa)
+{
+       qRegisterMetaType<KeySymbol>("KeySymbol");
+       qRegisterMetaType<KeyModifier>("KeyModifier");
+       connect(wa, &GuiWorkArea::compressKeySym, this, &CompressorProxy::slot,
+               Qt::QueuedConnection);
+       connect(this, &CompressorProxy::signal, wa, &GuiWorkArea::processKeySym);
+}
+
+
+bool CompressorProxy::emitCheck(bool isAutoRepeat)
+{
+       flag_ = true;
+       if (isAutoRepeat)
+               QCoreApplication::sendPostedEvents(this, QEvent::MetaCall); // recurse
+       bool result = flag_;
+       flag_ = false;
+       return result;
+}
+
+
+void CompressorProxy::slot(KeySymbol sym, KeyModifier mod, bool isAutoRepeat)
+{
+       if (emitCheck(isAutoRepeat))
+               Q_EMIT signal(sym, mod);
+       else
+               LYXERR(Debug::KEY, "system is busy: autoRepeat key event ignored");
+}
+
+
 void GuiWorkArea::keyPressEvent(QKeyEvent * ev)
 {
        // this is also called for ShortcutOverride events. In this case, one must
@@ -1040,13 +1072,16 @@ void GuiWorkArea::keyPressEvent(QKeyEvent * ev)
        bool const act = (ev->type() != QEvent::ShortcutOverride);
 
        // Do not process here some keys if dialog_mode_ is set
-       if (d->dialog_mode_
+       bool const for_dialog_mode = d->dialog_mode_
                && (ev->modifiers() == Qt::NoModifier
                    || ev->modifiers() == Qt::ShiftModifier)
                && (ev->key() == Qt::Key_Escape
                    || ev->key() == Qt::Key_Enter
-                   || ev->key() == Qt::Key_Return)
-           ) {
+                   || ev->key() == Qt::Key_Return);
+       // also do not use autoRepeat to input shortcuts
+       bool const autoRepeat = ev->isAutoRepeat();
+
+       if (for_dialog_mode || (!act && autoRepeat)) {
                ev->ignore();
                return;
        }
@@ -1063,51 +1098,31 @@ void GuiWorkArea::keyPressEvent(QKeyEvent * ev)
                }
        }
 
-       // do nothing if there are other events
-       // (the auto repeated events come too fast)
-       // it looks like this is only needed on X11
-#if defined(Q_WS_X11) || defined(QPA_XCB)
-       // FIXME: this is a weird way to implement event compression. Also, this is
-       // broken with IBus.
-       if (act && qApp->hasPendingEvents() && ev->isAutoRepeat()) {
-               switch (ev->key()) {
-               case Qt::Key_PageDown:
-               case Qt::Key_PageUp:
-               case Qt::Key_Left:
-               case Qt::Key_Right:
-               case Qt::Key_Up:
-               case Qt::Key_Down:
-                       LYXERR(Debug::KEY, "system is busy: scroll key event ignored");
-                       ev->ignore();
-                       return;
-               }
-       }
-#endif
-
        KeyModifier const m = q_key_state(ev->modifiers());
 
-       std::string str;
-       if (m & ShiftModifier)
-               str += "Shift-";
-       if (m & ControlModifier)
-               str += "Control-";
-       if (m & AltModifier)
-               str += "Alt-";
-       if (m & MetaModifier)
-               str += "Meta-";
-
-       if (act)
+       if (act && lyxerr.debugging(Debug::KEY)) {
+               std::string str;
+               if (m & ShiftModifier)
+                       str += "Shift-";
+               if (m & ControlModifier)
+                       str += "Control-";
+               if (m & AltModifier)
+                       str += "Alt-";
+               if (m & MetaModifier)
+                       str += "Meta-";
                LYXERR(Debug::KEY, " count: " << ev->count() << " text: " << ev->text()
                       << " isAutoRepeat: " << ev->isAutoRepeat() << " key: " << ev->key()
                       << " keyState: " << str);
+       }
 
        KeySymbol sym;
        setKeySymbol(&sym, ev);
        if (sym.isOK()) {
                if (act) {
-                       processKeySym(sym, m);
+                       Q_EMIT compressKeySym(sym, m, autoRepeat);
                        ev->accept();
                } else
+                       // here, !autoRepeat, as determined at the beginning
                        ev->setAccepted(queryKeySym(sym, m));
        } else {
                ev->ignore();

diff --git a/src/frontends/qt4/GuiWorkArea.h b/src/frontends/qt4/GuiWorkArea.h
index 4fd524909c55864d8828dc68b00e14b3e508c693..806aefd1613f6c9917d7b4386157b83a3974ba03 100644 (file)
--- a/src/frontends/qt4/GuiWorkArea.h
+++ b/src/frontends/qt4/GuiWorkArea.h
@@ -16,6 +16,7 @@
 #include "ui_WorkAreaUi.h"
 
 #include "frontends/WorkArea.h"
+#include "frontends/KeySymbol.h"
 
 #include <QAbstractScrollArea>
 #include <QTabBar>
@@ -97,6 +98,8 @@ Q_SIGNALS:
        void busy(bool);
        ///
        void bufferViewChanged();
+       /// send key event to CompressorProxy
+       void compressKeySym(KeySymbol sym, KeyModifier mod, bool isAutoRepeat);
 
 private Q_SLOTS:
        /// Scroll the BufferView.
@@ -157,6 +160,23 @@ private:
 }; // GuiWorkArea
 
 
+/// CompressorProxy adapted from Kuba Ober https://stackoverflow.com/a/21006207
+class CompressorProxy : public QObject
+{
+    Q_OBJECT
+       bool emitCheck(bool isAutoRepeat);
+       bool flag_;
+       // input: event to compress
+       Q_SLOT void slot(KeySymbol sym, KeyModifier mod, bool isAutoRepeat);
+       // output: compressed event
+    Q_SIGNAL void signal(KeySymbol sym, KeyModifier mod);
+public:
+    // No default constructor, since the proxy must be a child of the
+    // target object.
+       explicit CompressorProxy(GuiWorkArea * wa);
+};
+
+
 class EmbeddedWorkArea : public GuiWorkArea
 {
        Q_OBJECT