From: Guillaume Munch <gm@lyx.org>
Date: Fri, 29 Apr 2016 23:25:46 +0000 (+0100)
Subject: TocWidget: Fix perf regression
X-Git-Tag: 2.2.1~133
X-Git-Url: https://git.lyx.org/gitweb/?a=commitdiff_plain;h=009dc75fef382738acdf00a2a749293f56a125eb;p=features.git

TocWidget: Fix perf regression

4d1ad336 fixed #9754 but caused perf issues by cancelling the gains of having a
timer (introduced after #7138). This introduces in GuiToc::enableView() a
lightweight check of whether the widget should be updated. The logic is inspired
from GuiViewSource::enableView().
---

diff --git a/src/frontends/qt4/GuiToc.cpp b/src/frontends/qt4/GuiToc.cpp
index f603c56716..7d9b1e5646 100644
--- a/src/frontends/qt4/GuiToc.cpp
+++ b/src/frontends/qt4/GuiToc.cpp
@@ -66,9 +66,12 @@ void GuiToc::dispatchParams()
 }
 
 
-void GuiToc::enableView(bool /*enable*/)
+void GuiToc::enableView(bool enable)
 {
-	widget_->updateViewForce();
+	widget_->checkModelChanged();
+	if (!enable)
+		// In the opposite case, updateView() will be called anyway.
+		widget_->updateViewForce();
 }
 
 
diff --git a/src/frontends/qt4/TocWidget.cpp b/src/frontends/qt4/TocWidget.cpp
index 24bc433776..e3693b7313 100644
--- a/src/frontends/qt4/TocWidget.cpp
+++ b/src/frontends/qt4/TocWidget.cpp
@@ -452,6 +452,14 @@ void TocWidget::updateViewForce()
 }
 
 
+void TocWidget::checkModelChanged()
+{
+	if (!gui_view_.documentBufferView() ||
+	    gui_view_.tocModels().model(current_type_) != tocTV->model())
+		updateViewForce();
+}
+
+
 void TocWidget::filterContents()
 {
 	if (!tocTV->model())
diff --git a/src/frontends/qt4/TocWidget.h b/src/frontends/qt4/TocWidget.h
index 962c21a238..39a6c2926a 100644
--- a/src/frontends/qt4/TocWidget.h
+++ b/src/frontends/qt4/TocWidget.h
@@ -42,6 +42,8 @@ public:
 	///
 	bool getStatus(Cursor & cur, FuncRequest const & fr, FuncStatus & status)
 		const;
+	// update the view when the model has changed
+	void checkModelChanged();
 
 public Q_SLOTS:
 	/// Schedule new update of the display unless already scheduled.