src/java.desktop/windows/native/libawt/windows/awt_DnDDS.cpp

rev 58018 : 8238575: DragSourceEvent.getLocation() returns wrong value on HiDPI screens (Windows)
Reviewed-by: XXX

@@ -1,7 +1,7 @@
 /*
- * Copyright (c) 1997, 2016, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 1997, 2020, Oracle and/or its affiliates. All rights reserved.
  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
  *
  * This code is free software; you can redistribute it and/or modify it
  * under the terms of the GNU General Public License version 2 only, as
  * published by the Free Software Foundation.  Oracle designates this

@@ -280,11 +280,11 @@
     }
     dragSource->m_dwPerformedDropEffect = DROPEFFECT_NONE;
 
     call_dSCddfinished(env, peer, res == DRAGDROP_S_DROP && effects != DROPEFFECT_NONE,
                        convertDROPEFFECTToActions(effects),
-                       dragSource->m_dragPoint.x, dragSource->m_dragPoint.y);
+                       dragSource->m_dragPoint);
 
     env->DeleteLocalRef(peer);
 
     DASSERT(AwtDropTarget::IsCurrentDnDDataObject(dragSource));
     AwtDropTarget::SetCurrentDnDDataObject(NULL);

@@ -647,12 +647,11 @@
 
     ::GetCursorPos(&dragPoint);
 
     if ( (dragPoint.x != m_dragPoint.x || dragPoint.y != m_dragPoint.y) &&
          m_lastmods == modifiers) {//cannot move before cursor change
-        call_dSCmouseMoved(env, m_peer,
-                           m_actions, modifiers, dragPoint.x, dragPoint.y);
+        call_dSCmouseMoved(env, m_peer, m_actions, modifiers, dragPoint);
         JNU_CHECK_EXCEPTION_RETURN(env, E_UNEXPECTED);
         m_dragPoint = dragPoint;
     }
 
     if ((modifiers & JAVA_BUTTON_MASK) == 0) {

@@ -660,12 +659,11 @@
     } else if (m_initmods == 0) {
         m_initmods = modifiers;
     } else if ((modifiers & JAVA_BUTTON_MASK) != (m_initmods & JAVA_BUTTON_MASK)) {
         return DRAGDROP_S_CANCEL;
     } else if (m_lastmods != modifiers) {
-        call_dSCchanged(env, m_peer,
-                        m_actions, modifiers, dragPoint.x, dragPoint.y);
+        call_dSCchanged(env, m_peer, m_actions, modifiers, dragPoint);
         m_bRestoreNodropCustomCursor = TRUE;
     }
 
     m_lastmods = modifiers;
 

@@ -724,17 +722,17 @@
     int invalid = (dwEffect == DROPEFFECT_NONE);
 
     if (invalid) {
         // Don't call dragExit if dragEnter and dragOver haven't been called.
         if (!m_enterpending) {
-            call_dSCexit(env, m_peer, curs.x, curs.y);
+            call_dSCexit(env, m_peer, curs);
         }
         m_droptarget = (HWND)NULL;
         m_enterpending = TRUE;
     } else if (m_droptarget != NULL) {
         (*(m_enterpending ? call_dSCenter : call_dSCmotion))
-            (env, m_peer, m_actions, modifiers, curs.x, curs.y);
+            (env, m_peer, m_actions, modifiers, curs);
 
         m_enterpending = FALSE;
     }
 
     if (m_droptarget != NULL) {

@@ -1174,79 +1172,96 @@
     pmedium->pUnkForRelease = (IUnknown *)NULL;
 
     return S_OK;
 }
 
+static void ScaleDown(POINT &pt) {
+    HMONITOR monitor = MonitorFromPoint(pt, MONITOR_DEFAULTTOPRIMARY);
+    int screen = AwtWin32GraphicsDevice::GetScreenFromHMONITOR(monitor);
+    Devices::InstanceAccess devices;
+    AwtWin32GraphicsDevice *device = devices->GetDevice(screen);
+    if (device) {
+        pt.x = device->ScaleDownX(pt.x);
+        pt.y = device->ScaleDownY(pt.y);
+    }
+}
+
 DECLARE_JAVA_CLASS(dSCClazz, "sun/awt/windows/WDragSourceContextPeer")
 
 void
 AwtDragSource::call_dSCenter(JNIEnv* env, jobject self, jint targetActions,
-                             jint modifiers, jint x, jint y) {
+                             jint modifiers, POINT pt) {
+    ScaleDown(pt);
     DECLARE_VOID_JAVA_METHOD(dSCenter, dSCClazz, "dragEnter", "(IIII)V");
     DASSERT(!JNU_IsNull(env, self));
-    env->CallVoidMethod(self, dSCenter, targetActions, modifiers, x, y);
+    env->CallVoidMethod(self, dSCenter, targetActions, modifiers, pt.x, pt.y);
     if (!JNU_IsNull(env, safe_ExceptionOccurred(env))) {
         env->ExceptionDescribe();
         env->ExceptionClear();
     }
 }
 
 void
 AwtDragSource::call_dSCmotion(JNIEnv* env, jobject self, jint targetActions,
-                              jint modifiers, jint x, jint y) {
+                              jint modifiers, POINT pt) {
+    ScaleDown(pt);
     DECLARE_VOID_JAVA_METHOD(dSCmotion, dSCClazz, "dragMotion", "(IIII)V");
     DASSERT(!JNU_IsNull(env, self));
-    env->CallVoidMethod(self, dSCmotion, targetActions, modifiers, x, y);
+    env->CallVoidMethod(self, dSCmotion, targetActions, modifiers, pt.x, pt.y);
     if (!JNU_IsNull(env, safe_ExceptionOccurred(env))) {
         env->ExceptionDescribe();
         env->ExceptionClear();
     }
 }
 
 void
 AwtDragSource::call_dSCchanged(JNIEnv* env, jobject self, jint targetActions,
-                               jint modifiers, jint x, jint y) {
+                               jint modifiers, POINT pt) {
+    ScaleDown(pt);
     DECLARE_VOID_JAVA_METHOD(dSCchanged, dSCClazz, "operationChanged",
                              "(IIII)V");
     DASSERT(!JNU_IsNull(env, self));
-    env->CallVoidMethod(self, dSCchanged, targetActions, modifiers, x, y);
+    env->CallVoidMethod(self, dSCchanged, targetActions, modifiers, pt.x, pt.y);
     if (!JNU_IsNull(env, safe_ExceptionOccurred(env))) {
         env->ExceptionDescribe();
         env->ExceptionClear();
     }
 }
 
 void
-AwtDragSource::call_dSCexit(JNIEnv* env, jobject self, jint x, jint y) {
+AwtDragSource::call_dSCexit(JNIEnv* env, jobject self, POINT pt) {
+    ScaleDown(pt);
     DECLARE_VOID_JAVA_METHOD(dSCexit, dSCClazz, "dragExit", "(II)V");
     DASSERT(!JNU_IsNull(env, self));
-    env->CallVoidMethod(self, dSCexit, x, y);
+    env->CallVoidMethod(self, dSCexit, pt.x, pt.y);
     if (!JNU_IsNull(env, safe_ExceptionOccurred(env))) {
         env->ExceptionDescribe();
         env->ExceptionClear();
     }
 }
 
 void
 AwtDragSource::call_dSCddfinished(JNIEnv* env, jobject self, jboolean success,
-                                  jint operations, jint x, jint y) {
+                                  jint operations, POINT pt) {
+    ScaleDown(pt);
     DECLARE_VOID_JAVA_METHOD(dSCddfinished, dSCClazz, "dragDropFinished", "(ZIII)V");
     DASSERT(!JNU_IsNull(env, self));
-    env->CallVoidMethod(self, dSCddfinished, success, operations, x, y);
+    env->CallVoidMethod(self, dSCddfinished, success, operations, pt.x, pt.y);
     if (!JNU_IsNull(env, safe_ExceptionOccurred(env))) {
         env->ExceptionDescribe();
         env->ExceptionClear();
     }
 }
 
 void
 AwtDragSource::call_dSCmouseMoved(JNIEnv* env, jobject self, jint targetActions,
-                                  jint modifiers, jint x, jint y) {
+                                  jint modifiers, POINT pt) {
+    ScaleDown(pt);
     DECLARE_VOID_JAVA_METHOD(dSCmouseMoved, dSCClazz, "dragMouseMoved",
                              "(IIII)V");
     DASSERT(!JNU_IsNull(env, self));
-    env->CallVoidMethod(self, dSCmouseMoved, targetActions, modifiers, x, y);
+    env->CallVoidMethod(self, dSCmouseMoved, targetActions, modifiers, pt.x, pt.y);
     if (!JNU_IsNull(env, safe_ExceptionOccurred(env))) {
         env->ExceptionDescribe();
         env->ExceptionClear();
     }
 }