Bug 480639: Provide monitor-specific DPI scaling / zoom level

Added API Monitor.getZoom() to get zoom on Mac & Windows

Change-Id: Ib1990d0cbb2190323f7204dd14c6674d99278efd
Signed-off-by: Lakshmi Shanmugam <lshanmug@in.ibm.com>

1 files changed, 42 insertions, 0 deletions

diff --git a/bundles/org.eclipse.swt/Eclipse SWT PI/win32/org/eclipse/swt/internal/win32/OS.java b/bundles/org.eclipse.swt/Eclipse SWT PI/win32/org/eclipse/swt/internal/win32/OS.java
index 0f6fd03e7b..620a81f219 100644
--- a/bundles/org.eclipse.swt/Eclipse SWT PI/win32/org/eclipse/swt/internal/win32/OS.java
+++ b/bundles/org.eclipse.swt/Eclipse SWT PI/win32/org/eclipse/swt/internal/win32/OS.java
@@ -958,6 +958,7 @@ public class OS extends C {
 	public static final int MCN_SELECT = MCN_FIRST + 4;
 	public static final int MCS_NOTODAY = 0x0010;
 	public static final int MDIS_ALLCHILDSTYLES = 0x0001;
+	public static final int MDT_EFFECTIVE_DPI = 0;
 	public static final int MFS_CHECKED = 0x8;
 	public static final int MFS_DISABLED = 0x3;
 	public static final int MFS_GRAYED = 0x3;
@@ -2166,6 +2167,26 @@ public static final native int WINDOWPLACEMENT_sizeof ();
 public static final native int WINDOWPOS_sizeof ();
 public static final native int WNDCLASS_sizeof ();
 
+public static final int GetDpiForMonitor (long /*int*/ hmonitor, int dpiType, int [] dpiX, int [] dpiY) {
+		TCHAR lpLibFileName = new TCHAR (0, "Shcore.dll", true); //$NON-NLS-1$
+		long /*int*/ hModule = OS.LoadLibrary (lpLibFileName);
+		if (hModule != 0) {
+			String name = "GetDpiForMonitor\0"; //$NON-NLS-1$
+			byte [] lpProcName = new byte [name.length ()];
+			for (int i=0; i<lpProcName.length; i++) {
+				lpProcName [i] = (byte) name.charAt (i);
+			}
+			long /*int*/ DllGetDpiForMonitor = OS.GetProcAddress (hModule, lpProcName);
+			if (DllGetDpiForMonitor != 0) {
+				dpiX [0] = dpiY [0] = -1;
+	 			OS.Call (DllGetDpiForMonitor, hmonitor, dpiType, dpiX, dpiY);
+			}
+			OS.FreeLibrary (hModule);
+			return dpiX [0] == -1 ? -1 : 0; // return result if API call succeeded
+		}
+		return -1;
+}
+
 /** Ansi/Unicode wrappers */
 
 public static final long /*int*/ AddFontResourceEx (TCHAR lpszFilename, int fl, long /*int*/ pdv) {
@@ -2679,6 +2700,15 @@ public static final long /*int*/ LoadImage (long /*int*/ hinst, long /*int*/ lps
 	return LoadImageA (hinst, lpszName, uType, cxDesired, cyDesired, fuLoad);
 }
 
+public static final long /*int*/ LoadLibrary (TCHAR lpLibFileName) {
+	if (IsUnicode) {
+		char [] lpLibFileName1 = lpLibFileName == null ? null : lpLibFileName.chars;
+		return LoadLibraryW (lpLibFileName1);
+	}
+	byte [] lpLibFileName1 = lpLibFileName == null ? null : lpLibFileName.bytes;
+	return LoadLibraryA (lpLibFileName1);
+}
+
 public static final int MapVirtualKey (int uCode, int uMapType) {
 	if (IsUnicode) return MapVirtualKeyW (uCode, uMapType);
 	return MapVirtualKeyA (uCode, uMapType);
@@ -3253,6 +3283,7 @@ public static final native boolean BringWindowToTop (long /*int*/ hWnd);
 public static final native int BufferedPaintInit ();
 /** @method flags=dynamic */
 public static final native int BufferedPaintUnInit ();
+public static native void Call (long /*int*/ address, long /*int*/ hmonitor, int dpiType, int[] dpiX, int[] dpiY);
 /**
  * @param hhk cast=(HHOOK)
  * @param wParam cast=(WPARAM)
@@ -3743,6 +3774,8 @@ public static final native int FormatMessageA (int dwFlags, long /*int*/ lpSourc
  * @param Arguments cast=(va_list*)
  */
 public static final native int FormatMessageW (int dwFlags, long /*int*/ lpSource, int dwMessageId, int dwLanguageId, long /*int*/ [] lpBuffer, int nSize, long /*int*/ Arguments);
+/** @param hLibModule cast=(HMODULE) */
+public static final native boolean FreeLibrary (long /*int*/ hLibModule);
 /** @param dwLimit cast=(DWORD) */
 public static final native int GdiSetBatchLimit (int dwLimit);
 public static final native int GET_WHEEL_DELTA_WPARAM(long /*int*/ wParam);
@@ -4054,6 +4087,11 @@ public static final native boolean OpenPrinterW (char[] pPrinterName, long /*int
  * @param pDefault cast=(LPPRINTER_DEFAULTS)
  */
 public static final native boolean OpenPrinterA (byte[] pPrinterName, long /*int*/ [] phPrinter, long /*int*/ pDefault);
+/**
+ * @param hModule cast=(HMODULE)
+ * @param lpProcName cast=(LPCTSTR)
+ */
+public static final native long /*int*/ GetProcAddress (long /*int*/ hModule, byte [] lpProcName);
 public static final native long /*int*/ GetProcessHeap ();
 /**
  * @param lpAppName cast=(LPWSTR)
@@ -4494,6 +4532,10 @@ public static final native long /*int*/ LoadImageW (long /*int*/ hinst, long /*i
  * @param lpszName cast=(LPSTR)
  */
 public static final native long /*int*/ LoadImageA (long /*int*/ hinst, long /*int*/ lpszName, int uType, int cxDesired, int cyDesired, int fuLoad);
+/** @param lpLibFileName cast=(LPWSTR) */
+public static final native long /*int*/ LoadLibraryW (char [] lpLibFileName);
+/** @param lpLibFileName cast=(LPSTR) */
+public static final native long /*int*/ LoadLibraryA (byte [] lpLibFileName);
 /** @param hMem cast=(HLOCAL) */
 public static final native long /*int*/ LocalFree (long /*int*/ hMem);
 public static final native int LODWORD (long l);