[LyX/2.1.1-staging] Draw a small red frame around preview images that are too small. (cherry picked from commit 1bb7c3baafb636eb02c09ee651b4f7b7a5836b04)

[Richard Heck]

commit 3da5fe4413f9b4ce091532140da9dffd29f62a4a
Author: Richard Heck <***@lyx.org>
Date: Wed Mar 19 12:43:21 2014 -0400

Draw a small red frame around preview images that are too small.
(cherry picked from commit 1bb7c3baafb636eb02c09ee651b4f7b7a5836b04)

diff --git a/src/mathed/InsetMathHull.cpp b/src/mathed/InsetMathHull.cpp
index e994d44..4c20625 100644
--- a/src/mathed/InsetMathHull.cpp
+++ b/src/mathed/InsetMathHull.cpp
@@ -44,6 +44,7 @@
#include "insets/InsetRef.h"
#include "insets/RenderPreview.h"

+#include "graphics/GraphicsImage.h"
#include "graphics/PreviewImage.h"
#include "graphics/PreviewLoader.h"

@@ -410,7 +411,7 @@ ColorCode InsetMathHull::standardColor() const
}


-bool InsetMathHull::previewState(BufferView * bv) const
+bool InsetMathHull::previewState(const BufferView *const bv) const
{
if (!editing(bv) && RenderPreview::status() == LyXRC::PREVIEW_ON
&& type_ != hullRegexp)
@@ -423,14 +424,24 @@ bool InsetMathHull::previewState(BufferView * bv) const
}


+namespace {
+static const int ERROR_FRAME_WIDTH = 2;
+}
+
void InsetMathHull::metrics(MetricsInfo & mi, Dimension & dim) const
{
if (previewState(mi.base.bv)) {
preview_->metrics(mi, dim);
- // insert a one pixel gap in front of the formula
- dim.wid += 1;
- if (display())
- dim.des += displayMargin();
+ if (previewTooSmall(dim)) {
+ // preview image is too small
+ dim.wid += 2 * ERROR_FRAME_WIDTH;
+ dim.asc += 2 * ERROR_FRAME_WIDTH;
+ } else {
+ // insert a one pixel gap in front of the formula
+ dim.wid += 1;
+ if (display())
+ dim.des += displayMargin();
+ }
// Cache the inset dimension.
setDimCache(mi, dim);
return;
@@ -471,10 +482,21 @@ void InsetMathHull::metrics(MetricsInfo & mi, Dimension & dim) const
}


+bool InsetMathHull::previewTooSmall(Dimension const & dim) const
+{
+ return dim.width() <= 10 && dim.height() <= 10;
+}
+
+
ColorCode InsetMathHull::backgroundColor(PainterInfo const & pi) const
{
- if (previewState(pi.base.bv))
+ BufferView const * const bv = pi.base.bv;
+ if (previewState(bv)) {
+ Dimension const dim = dimension(*pi.base.bv);
+ if (previewTooSmall(dim))
+ return Color_error;
return graphics::PreviewLoader::backgroundColor();
+ }
return Color_mathbg;
}

@@ -482,23 +504,36 @@ ColorCode InsetMathHull::backgroundColor(PainterInfo const & pi) const
void InsetMathHull::drawBackground(PainterInfo & pi, int x, int y) const
{
Dimension const dim = dimension(*pi.base.bv);
+ if (previewTooSmall(dim)) {
+ pi.pain.fillRectangle(x, y - 2 * ERROR_FRAME_WIDTH,
+ dim.wid, dim.asc + dim.des, backgroundColor(pi));
+ return;
+ }
pi.pain.fillRectangle(x + 1, y - dim.asc + 1, dim.wid - 2,
- dim.asc + dim.des - 1, pi.backgroundColor(this));
+ dim.asc + dim.des - 1, backgroundColor(pi));
}


void InsetMathHull::draw(PainterInfo & pi, int x, int y) const
{
- use_preview_ = previewState(pi.base.bv);
+ BufferView const * const bv = pi.base.bv;
+ use_preview_ = previewState(bv);

if (type_ == hullRegexp) {
- Dimension const dim = dimension(*pi.base.bv);
+ Dimension const dim = dimension(*bv);
pi.pain.rectangle(x + 1, y - dim.ascent() + 1,
dim.width() - 2, dim.height() - 2, Color_regexpframe);
}
+
if (use_preview_) {
- // one pixel gap in front
- preview_->draw(pi, x + 1, y);
+ Dimension const dim = dimension(*bv);
+ if (previewTooSmall(dim)) {
+ // we have an extra frame
+ preview_->draw(pi, x + ERROR_FRAME_WIDTH, y);
+ } else {
+ // one pixel gap in front
+ preview_->draw(pi, x + 1, y);
+ }
setPosCache(pi, x, y);
return;
}
diff --git a/src/mathed/InsetMathHull.h b/src/mathed/InsetMathHull.h
index af00eaf..0cffffd 100644
--- a/src/mathed/InsetMathHull.h
+++ b/src/mathed/InsetMathHull.h
@@ -271,7 +271,9 @@ protected:
///
void handleFont2(Cursor & cur, docstring const & arg);
///
- bool previewState(BufferView * bv) const;
+ bool previewState(BufferView const * const bv) const;
+ ///
+ bool previ