From 322be3bee0a03f5f8a037f1f744e6663ccda42d6 Mon Sep 17 00:00:00 2001
From: Pascal Abresch <nep@packageloss.eu>
Date: Sun, 25 Jul 2021 15:03:20 +0200
Subject: [PATCH] StatusView: compute font size based on scrollbar size

Compute a font size that just fits the available space, instead of using
an arbitrary scaling. This makes the code adjust to any font and any UI
size.

Select the appropriate font using a binary search, which will need only
a few attempts (I think 6 font sizes will be tried at the default
config)

Change-Id: Ie3b8678678c0d940981f1785418aa8ab354d01c5
Reviewed-on: https://review.haiku-os.org/c/haiku/+/3893
Reviewed-by: waddlesplash <waddlesplash@gmail.com>
Tested-by: Commit checker robot <no-reply+buildbot@haiku-os.org>
---
 headers/private/shared/StatusView.h |  5 ++++
 src/apps/stylededit/StatusView.cpp  |  3 ++-
 src/kits/shared/Jamfile             |  1 +
 src/kits/shared/StatusView.cpp      | 41 +++++++++++++++++++++++++++++
 4 files changed, 49 insertions(+), 1 deletion(-)
 create mode 100644 headers/private/shared/StatusView.h
 create mode 100644 src/kits/shared/StatusView.cpp

diff --git a/headers/private/shared/StatusView.h b/headers/private/shared/StatusView.h
new file mode 100644
index 0000000000..9a96dc5494
--- /dev/null
+++ b/headers/private/shared/StatusView.h
@@ -0,0 +1,5 @@
+namespace BPrivate {
+
+void AdoptScrollBarFontSize(BView*);
+
+} // namespace BPrivate
diff --git a/src/apps/stylededit/StatusView.cpp b/src/apps/stylededit/StatusView.cpp
index 243d333b3e..c13d39a931 100644
--- a/src/apps/stylededit/StatusView.cpp
+++ b/src/apps/stylededit/StatusView.cpp
@@ -9,6 +9,7 @@
 
 
 #include "StatusView.h"
+#include <StatusView.h>
 
 #include <stdio.h>
 #include <stdlib.h>
@@ -63,7 +64,7 @@ void
 StatusView::AttachedToWindow()
 {
 	SetFont(be_plain_font);
-	SetFontSize(ceilf(be_plain_font->Size() * 0.83f));
+	BPrivate::AdoptScrollBarFontSize(this);
 
 	BMessage message(UPDATE_STATUS);
 	message.AddInt32("line", 1);
diff --git a/src/kits/shared/Jamfile b/src/kits/shared/Jamfile
index aea432cbe7..bf0e23b2c4 100644
--- a/src/kits/shared/Jamfile
+++ b/src/kits/shared/Jamfile
@@ -59,6 +59,7 @@ for architectureObject in [ MultiArchSubDirSetup ] {
 			SettingsHandler.cpp
 			SettingsMessage.cpp
 			ShakeTrackingFilter.cpp
+			StatusView.cpp
 			StringForRate.cpp
 			StringForSize.cpp
 			StripeView.cpp
diff --git a/src/kits/shared/StatusView.cpp b/src/kits/shared/StatusView.cpp
new file mode 100644
index 0000000000..542799278c
--- /dev/null
+++ b/src/kits/shared/StatusView.cpp
@@ -0,0 +1,41 @@
+/*
+ * Copyright 2021, Pascal R. G. Abresch, nep@packageloss.eu.
+ * Distributed under the terms of the MIT License.
+ */
+
+#include <ControlLook.h>
+#include <View.h>
+
+
+namespace BPrivate {
+
+
+void
+AdoptScrollBarFontSize(BView* view)
+{
+	float maxSize = be_control_look->GetScrollBarWidth();
+	BFont testFont = be_plain_font;
+	float currentSize;
+	font_height fontHeight;
+
+	float minFontSize = 0.0f;
+	float maxFontSize = 48.0f;
+
+	while (maxFontSize - minFontSize > 1.0f) {
+		float midFontSize = (maxFontSize + minFontSize) / 2.0f;
+
+		testFont.SetSize(midFontSize);
+		testFont.GetHeight(&fontHeight);
+		currentSize = fontHeight.ascent + fontHeight.descent;
+
+		if (currentSize > maxSize)
+			maxFontSize = midFontSize;
+		else
+			minFontSize = midFontSize;
+	}
+
+	view->SetFontSize(minFontSize);
+}
+
+
+} // namespace BPrivate