From: Jean-Marc Lasgouttes <lasgouttes@lyx.org>
Date: Mon, 7 Oct 2019 10:31:20 +0000 (+0200)
Subject: Fix bad caret position with horizontal scrolling
X-Git-Url: https://git.lyx.org/gitweb/?a=commitdiff_plain;h=6b68fb5ff71e15007d5c71cfec650d4824036e25;p=features.git

Fix bad caret position with horizontal scrolling

Horizontal scrolling used to be taken into account when updating caret
geometry. This is wrong since it may have changed when time comes to
draw the caret. This leads to a situation where the first apparition
of the caret is at a wrong place.

Now the extra horizontal offset is used at drawing time.

Fixes bug #11603.
---

diff --git a/src/frontends/qt/GuiWorkArea.cpp b/src/frontends/qt/GuiWorkArea.cpp
index 6a7c995da9..e2772fbb60 100644
--- a/src/frontends/qt/GuiWorkArea.cpp
+++ b/src/frontends/qt/GuiWorkArea.cpp
@@ -133,26 +133,30 @@ public:
 		x_(0), caret_width_(0)
 	{}
 
-	void draw(QPainter & painter)
+	/* Draw he caret. Parameter \c horiz_offset is not 0 when there
+	 * has been horizontal scrolling in current row
+	 */
+	void draw(QPainter & painter, int horiz_offset)
 	{
 		if (!rect_.isValid())
 			return;
 
-		int y = rect_.top();
-		int l = x_ - rect_.left();
-		int r = rect_.right() - x_;
-		int bot = rect_.bottom();
+		int const x = x_ - horiz_offset;
+		int const y = rect_.top();
+		int const l = x_ - rect_.left();
+		int const r = rect_.right() - x_;
+		int const bot = rect_.bottom();
 
 		// draw vertical line
-		painter.fillRect(x_, y, caret_width_, rect_.height(), color_);
+		painter.fillRect(x, y, caret_width_, rect_.height(), color_);
 
 		// draw RTL/LTR indication
 		painter.setPen(color_);
 		if (l_shape_) {
 			if (rtl_)
-				painter.drawLine(x_, bot, x_ - l + 1, bot);
+				painter.drawLine(x, bot, x - l + 1, bot);
 			else
-				painter.drawLine(x_, bot, x_ + caret_width_ + r - 1, bot);
+				painter.drawLine(x, bot, x + caret_width_ + r - 1, bot);
 		}
 
 		// draw completion triangle
@@ -160,11 +164,11 @@ public:
 			int m = y + rect_.height() / 2;
 			int d = TabIndicatorWidth - 1;
 			if (rtl_) {
-				painter.drawLine(x_ - 1, m - d, x_ - 1 - d, m);
-				painter.drawLine(x_ - 1, m + d, x_ - 1 - d, m);
+				painter.drawLine(x - 1, m - d, x - 1 - d, m);
+				painter.drawLine(x - 1, m + d, x - 1 - d, m);
 			} else {
-				painter.drawLine(x_ + caret_width_, m - d, x_ + caret_width_ + d, m);
-				painter.drawLine(x_ + caret_width_, m + d, x_ + caret_width_ + d, m);
+				painter.drawLine(x + caret_width_, m - d, x + caret_width_ + d, m);
+				painter.drawLine(x + caret_width_, m + d, x + caret_width_ + d, m);
 			}
 		}
 	}
@@ -633,11 +637,6 @@ void GuiWorkArea::Private::updateCaretGeometry()
 		&& !completer_->inlineVisible();
 	caret_visible_ = true;
 
-	//int cur_x = buffer_view_->getPos(cur).x_;
-	// We may have decided to slide the cursor row so that caret
-	// is visible.
-	point.x_ -= buffer_view_->horizScrollOffset();
-
 	caret_->update(point.x_, point.y_, h, l_shape, isrtl, completable);
 }
 
@@ -1340,7 +1339,7 @@ void GuiWorkArea::paintEvent(QPaintEvent * ev)
 
 	// and the caret
 	if (d->caret_visible_)
-		d->caret_->draw(pain);
+		d->caret_->draw(pain, d->buffer_view_->horizScrollOffset());
 
 	d->updateScreen(ev->rect());