gecko-dev/widget/windows/nsScreenManagerWin.cpp

188 lines
4.9 KiB
C++

/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
/* This Source Code Form is subject to the terms of the Mozilla Public
* License, v. 2.0. If a copy of the MPL was not distributed with this
* file, You can obtain one at http://mozilla.org/MPL/2.0/. */
#include "nsScreenManagerWin.h"
#include "nsScreenWin.h"
#include "gfxWindowsPlatform.h"
#include "nsIWidget.h"
BOOL CALLBACK CountMonitors(HMONITOR, HDC, LPRECT, LPARAM ioCount);
nsScreenManagerWin::nsScreenManagerWin()
: mNumberOfScreens(0)
{
// nothing to do. I guess we could cache a bunch of information
// here, but we want to ask the device at runtime in case anything
// has changed.
}
nsScreenManagerWin::~nsScreenManagerWin()
{
}
// addref, release, QI
NS_IMPL_ISUPPORTS(nsScreenManagerWin, nsIScreenManager)
//
// CreateNewScreenObject
//
// Utility routine. Creates a new screen object from the given device handle
//
// NOTE: For this "single-monitor" impl, we just always return the cached primary
// screen. This should change when a multi-monitor impl is done.
//
nsIScreen*
nsScreenManagerWin::CreateNewScreenObject(HMONITOR inScreen)
{
nsIScreen* retScreen = nullptr;
// look through our screen list, hoping to find it. If it's not there,
// add it and return the new one.
for (unsigned i = 0; i < mScreenList.Length(); ++i) {
ScreenListItem& curr = mScreenList[i];
if (inScreen == curr.mMon) {
NS_IF_ADDREF(retScreen = curr.mScreen.get());
return retScreen;
}
} // for each screen.
retScreen = new nsScreenWin(inScreen);
mScreenList.AppendElement(ScreenListItem(inScreen, retScreen));
NS_IF_ADDREF(retScreen);
return retScreen;
}
NS_IMETHODIMP
nsScreenManagerWin::ScreenForId(uint32_t aId, nsIScreen **outScreen)
{
*outScreen = nullptr;
for (unsigned i = 0; i < mScreenList.Length(); ++i) {
ScreenListItem& curr = mScreenList[i];
uint32_t id;
nsresult rv = curr.mScreen->GetId(&id);
if (NS_SUCCEEDED(rv) && id == aId) {
NS_IF_ADDREF(*outScreen = curr.mScreen.get());
return NS_OK;
}
}
return NS_ERROR_FAILURE;
}
//
// ScreenForRect
//
// Returns the screen that contains the rectangle. If the rect overlaps
// multiple screens, it picks the screen with the greatest area of intersection.
//
// The coordinates are in pixels (not twips) and in logical screen coordinates.
//
NS_IMETHODIMP
nsScreenManagerWin::ScreenForRect(int32_t inLeft, int32_t inTop, int32_t inWidth, int32_t inHeight,
nsIScreen **outScreen)
{
if (!(inWidth || inHeight)) {
NS_WARNING("trying to find screen for sizeless window, using primary monitor");
*outScreen = CreateNewScreenObject(nullptr); // addrefs
return NS_OK;
}
// convert coordinates from logical to device pixels for MonitorFromRect
double dpiScale = nsIWidget::DefaultScaleOverride();
if (dpiScale <= 0.0) {
dpiScale = gfxWindowsPlatform::GetPlatform()->GetDPIScale();
}
RECT globalWindowBounds = {
NSToIntRound(dpiScale * inLeft),
NSToIntRound(dpiScale * inTop),
NSToIntRound(dpiScale * (inLeft + inWidth)),
NSToIntRound(dpiScale * (inTop + inHeight))
};
HMONITOR genScreen = ::MonitorFromRect(&globalWindowBounds, MONITOR_DEFAULTTOPRIMARY);
*outScreen = CreateNewScreenObject(genScreen); // addrefs
return NS_OK;
} // ScreenForRect
//
// GetPrimaryScreen
//
// The screen with the menubar/taskbar. This shouldn't be needed very
// often.
//
NS_IMETHODIMP
nsScreenManagerWin::GetPrimaryScreen(nsIScreen** aPrimaryScreen)
{
*aPrimaryScreen = CreateNewScreenObject(nullptr); // addrefs
return NS_OK;
} // GetPrimaryScreen
//
// CountMonitors
//
// Will be called once for every monitor in the system. Just
// increments the parameter, which holds a ptr to a PRUin32 holding the
// count up to this point.
//
BOOL CALLBACK
CountMonitors(HMONITOR, HDC, LPRECT, LPARAM ioParam)
{
uint32_t* countPtr = reinterpret_cast<uint32_t*>(ioParam);
++(*countPtr);
return TRUE; // continue the enumeration
} // CountMonitors
//
// GetNumberOfScreens
//
// Returns how many physical screens are available.
//
NS_IMETHODIMP
nsScreenManagerWin::GetNumberOfScreens(uint32_t *aNumberOfScreens)
{
if (mNumberOfScreens)
*aNumberOfScreens = mNumberOfScreens;
else {
uint32_t count = 0;
BOOL result = ::EnumDisplayMonitors(nullptr, nullptr, (MONITORENUMPROC)CountMonitors, (LPARAM)&count);
if (!result)
return NS_ERROR_FAILURE;
*aNumberOfScreens = mNumberOfScreens = count;
}
return NS_OK;
} // GetNumberOfScreens
NS_IMETHODIMP
nsScreenManagerWin::GetSystemDefaultScale(float *aDefaultScale)
{
*aDefaultScale = float(gfxWindowsPlatform::GetPlatform()->GetDPIScale());
return NS_OK;
}
NS_IMETHODIMP
nsScreenManagerWin::ScreenForNativeWidget(void *aWidget, nsIScreen **outScreen)
{
HMONITOR mon = MonitorFromWindow((HWND) aWidget, MONITOR_DEFAULTTOPRIMARY);
*outScreen = CreateNewScreenObject(mon);
return NS_OK;
}