From: Scott Kostyshak <skostysh@lyx.org>
Date: Sun, 8 Mar 2020 15:16:28 +0000 (-0400)
Subject: Fix Qt deprecation warns for setting tab
X-Git-Url: https://git.lyx.org/gitweb/?a=commitdiff_plain;h=752ec9185c9c53139b9704826222718104aea872;p=features.git

Fix Qt deprecation warns for setting tab

Fix warnings coming from deprecations of QTextEdit::tabStopWidth()
and QFontMetrics::width(). Regarding tabStopWidth(), the ChangeLog
states the following [1]:

  Introduced tabStopDistance property in QTextOption, QTextEdit and
  QPlainTextEdit as replacement for the inconsistently named tabStop and
  tabStopWidth properties. QTextOption::tabStop, QTextEdit::tabStopWidth and
  QPlainTextEdit::tabStopWidth are now deprecated.

Note that QFontMetrics::horizontalAdvance() is what we want here, as
opposed to QFontMetrics::boundingRect(), because we want to know
where to draw the next character after the tab.

[1] https://code.qt.io/cgit/qt/qtbase.git/tree/dist/changes-5.10.0/?h=v5.10.0
---

diff --git a/src/frontends/qt/GuiDocument.cpp b/src/frontends/qt/GuiDocument.cpp
index 2d1cc7628f..9ae68405f7 100644
--- a/src/frontends/qt/GuiDocument.cpp
+++ b/src/frontends/qt/GuiDocument.cpp
@@ -495,7 +495,13 @@ PreambleModule::PreambleModule(QWidget * parent)
 	// https://stackoverflow.com/questions/13027091/how-to-override-tab-width-in-qt
 	const int tabStop = 4;
 	QFontMetrics metrics(preambleTE->currentFont());
+#if (QT_VERSION >= QT_VERSION_CHECK(5, 11, 0))
+	// horizontalAdvance() is available starting in 5.11.0
+	// setTabStopDistance() is available starting in 5.10.0
+	preambleTE->setTabStopDistance(tabStop * metrics.horizontalAdvance(' '));
+#else
 	preambleTE->setTabStopWidth(tabStop * metrics.width(' '));
+#endif
 }