1 /* 2 * Copyright (c) 2016, 2019, Oracle and/or its affiliates. All rights reserved. 3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. 4 * 5 * This code is free software; you can redistribute it and/or modify it 6 * under the terms of the GNU General Public License version 2 only, as 7 * published by the Free Software Foundation. Oracle designates this 8 * particular file as subject to the "Classpath" exception as provided 9 * by Oracle in the LICENSE file that accompanied this code. 10 * 11 * This code is distributed in the hope that it will be useful, but WITHOUT 12 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or 13 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License 14 * version 2 for more details (a copy is included in the LICENSE file that 15 * accompanied this code). 16 * 17 * You should have received a copy of the GNU General Public License version 18 * 2 along with this work; if not, write to the Free Software Foundation, 19 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. 20 * 21 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA 22 * or visit www.oracle.com if you need additional information or have any 23 * questions. 24 */ 25 #include "systemScale.h" 26 #include <jdk_util.h> 27 #ifndef MDT_EFFECTIVE_DPI 28 #define MDT_EFFECTIVE_DPI 0 29 #endif 30 31 void GetScreenDpi(HMONITOR hmon, float *dpiX, float *dpiY) 32 { 33 unsigned x = 0; 34 unsigned y = 0; 35 36 // for debug purposes 37 static float scale = -2.0f; 38 if (scale == -2) { 39 scale = -1; 40 char *uiScale = getenv("J2D_UISCALE"); 41 if (uiScale != NULL) { 42 scale = (float)strtod(uiScale, NULL); 43 if (errno == ERANGE || scale <= 0) { 44 scale = -1; 45 } 46 } 47 } 48 49 if (scale > 0) { 50 *dpiX = *dpiY = scale; 51 return; 52 } 53 54 typedef HRESULT(WINAPI GetDpiForMonitorFunc)(HMONITOR, int, UINT*, UINT*); 55 static HMODULE hLibSHCoreDll = NULL; 56 static GetDpiForMonitorFunc *lpGetDpiForMonitor = NULL; 57 58 if (hLibSHCoreDll == NULL) { 59 hLibSHCoreDll = JDK_LoadSystemLibrary("shcore.dll"); 60 if (hLibSHCoreDll != NULL) { 61 lpGetDpiForMonitor = (GetDpiForMonitorFunc*)GetProcAddress( 62 hLibSHCoreDll, "GetDpiForMonitor"); 63 } 64 } 65 66 if (lpGetDpiForMonitor != NULL) { 67 HRESULT hResult = lpGetDpiForMonitor(hmon, 68 MDT_EFFECTIVE_DPI, &x, &y); 69 if (hResult == S_OK) { 70 *dpiX = static_cast<float>(x); 71 *dpiY = static_cast<float>(y); 72 } 73 } else { 74 HDC hdc = GetDC(NULL); 75 if (hdc) { 76 *dpiX = static_cast<float>(GetDeviceCaps(hdc, LOGPIXELSX)); 77 *dpiY = static_cast<float>(GetDeviceCaps(hdc, LOGPIXELSY)); 78 ReleaseDC(NULL, hdc); 79 } 80 } 81 return; 82 } 83 84 HMONITOR WINAPI getPrimaryMonitor() 85 { 86 const POINT point = { 0, 0 }; 87 return MonitorFromPoint(point, MONITOR_DEFAULTTOPRIMARY); 88 }