From f98e1cb9f0d401ff02f779906788d48a3fcdfd7c Mon Sep 17 00:00:00 2001
From: "Jason A. Donenfeld" <Jason@zx2c4.com>
Date: Thu, 16 May 2019 10:48:03 +0200
Subject: ui: react to DPI changes in syntax editor

Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>
---
 ui/syntax/syntaxedit.c  | 16 ++++++++++++----
 ui/syntax/syntaxedit.go |  6 ++++++
 ui/syntax/syntaxedit.h  |  1 +
 3 files changed, 19 insertions(+), 4 deletions(-)

(limited to 'ui')

diff --git a/ui/syntax/syntaxedit.c b/ui/syntax/syntaxedit.c
index cf2d1b33..0050af4c 100644
--- a/ui/syntax/syntaxedit.c
+++ b/ui/syntax/syntaxedit.c
@@ -22,6 +22,7 @@ struct syntaxedit_data {
 	IRichEditOle *irich;
 	ITextDocument *idoc;
 	enum block_state last_block_state;
+	LONG yheight;
 	bool highlight_guard;
 };
 
@@ -118,6 +119,7 @@ done:
 
 static void highlight_text(HWND hWnd)
 {
+	struct syntaxedit_data *this = (struct syntaxedit_data *)GetWindowLongPtr(hWnd, GWLP_USERDATA);
 	GETTEXTLENGTHEX gettextlengthex = {
 		.flags = GTL_NUMBYTES,
 		.codepage = CP_ACP /* Probably CP_UTF8 would be better, but (wine at least) returns utf32 sizes. */
@@ -130,10 +132,9 @@ static void highlight_text(HWND hWnd)
 		.cbSize = sizeof(CHARFORMAT2),
 		.dwMask = CFM_COLOR | CFM_CHARSET | CFM_SIZE | CFM_BOLD | CFM_ITALIC | CFM_UNDERLINE,
 		.dwEffects = CFE_AUTOCOLOR,
-		.yHeight = 20 * 10,
+		.yHeight = this->yheight ?: 20 * 10,
 		.bCharSet = ANSI_CHARSET
 	};
-	struct syntaxedit_data *this = (struct syntaxedit_data *)GetWindowLongPtr(hWnd, GWLP_USERDATA);
 	LRESULT msg_size;
 	char *msg = NULL;
 	struct highlight_span *spans = NULL;
@@ -318,9 +319,16 @@ static LRESULT CALLBACK child_proc(HWND hWnd, UINT Msg, WPARAM wParam, LPARAM lP
 		SendMessage(hWnd, EM_EMPTYUNDOBUFFER, 0, 0);
 		return ret;
 	}
-	case WM_DPICHANGED:
+	case SE_SET_PARENT_DPI: {
+		struct syntaxedit_data *this = (struct syntaxedit_data *)GetWindowLongPtr(hWnd, GWLP_USERDATA);
+		HDC hdc = GetDC(hWnd);
+		if (this->yheight)
+			SendMessage(hWnd, EM_SETZOOM, GetDeviceCaps(hdc, LOGPIXELSY), wParam);
+		this->yheight = MulDiv(20 * 10, wParam, GetDeviceCaps(hdc, LOGPIXELSY));
+		ReleaseDC(hWnd, hdc);
 		highlight_text(hWnd);
-		break;
+		return 0;
+	}
 	case WM_REFLECT + WM_COMMAND:
 	case WM_COMMAND:
 	case WM_REFLECT + WM_NOTIFY:
diff --git a/ui/syntax/syntaxedit.go b/ui/syntax/syntaxedit.go
index 67e132c4..62b4310b 100644
--- a/ui/syntax/syntaxedit.go
+++ b/ui/syntax/syntaxedit.go
@@ -15,6 +15,7 @@ import (
 	"github.com/lxn/win"
 )
 
+// #cgo LDFLAGS: -lgdi32
 // #include "syntaxedit.h"
 import "C"
 
@@ -108,6 +109,7 @@ func NewSyntaxEdit(parent walk.Container) (*SyntaxEdit, error) {
 	if err != nil {
 		return nil, err
 	}
+	se.SendMessage(C.SE_SET_PARENT_DPI, uintptr(parent.DPI()), 0)
 
 	se.GraphicsEffects().Add(walk.InteractionEffect)
 	se.GraphicsEffects().Add(walk.FocusEffect)
@@ -126,3 +128,7 @@ func NewSyntaxEdit(parent walk.Container) (*SyntaxEdit, error) {
 
 	return se, nil
 }
+
+func (se *SyntaxEdit) ApplyDPI(dpi int) {
+	se.SendMessage(C.SE_SET_PARENT_DPI, uintptr(dpi), 0)
+}
diff --git a/ui/syntax/syntaxedit.h b/ui/syntax/syntaxedit.h
index 7d158b29..048e7bc4 100644
--- a/ui/syntax/syntaxedit.h
+++ b/ui/syntax/syntaxedit.h
@@ -18,6 +18,7 @@
 
 #define SE_PRIVATE_KEY (WM_USER + 0x3100)
 #define SE_TRAFFIC_BLOCK (WM_USER + 0x3101)
+#define SE_SET_PARENT_DPI (WM_USER + 0x3102)
 
 enum block_state {
 	InevaluableBlockingUntunneledTraffic,
-- 
cgit v1.2.3-59-g8ed1b