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I made a program that has two different states, one is for menu display-"Menu State", and the other state is for drawing some stuff-"Draw State".
But I came across a weird thing, if i load certain png for texture and copy them to renderer to display , then leave "Menu State" to enter "Draw State". The texture will somehow make the rectangle color not display properly (for example make green go dark).
In my code, switching to a new state(invoke MenuState::onExit()) will erase the texture map(map of texture smart pointer indexing with std::string)
So the texutre loaded doesn't even exist in the "Drawing State".
I couldn't figure out what went wrong. Here is some of my codes
void TextureManager::DrawPixel(int x, int y, int width, int height, SDL_Renderer *pRenderer)
{
SDL_Rect rect;
rect.x = x;
rect.y = y;
rect.w = width;
rect.h = height;
SDL_SetRenderDrawColor(pRenderer, 0, 255, 0, 255);//same color value
SDL_RenderFillRect(pRenderer, &rect);
}
static bool TextureManagerLoadFile(std::string filename, std::string id)
{
return TextureManager::Instance().Load(filename, id, Game::Instance().GetRenderer());
}
bool TextureManager::Load(std::string filename, std::string id, SDL_Renderer *pRenderer)
{
if(m_textureMap.count(id) != 0)
{
return false;
}
SDL_Surface *pTempSurface = IMG_Load(filename.c_str());
SDL_Texture *pTexutre = SDL_CreateTextureFromSurface(pRenderer, pTempSurface);
SDL_FreeSurface(pTempSurface);
if(pTexutre != 0)
{
m_textureMap[id] = std::make_unique<textureData>(pTexutre, 0, 0);
SDL_QueryTexture(pTexutre, NULL, NULL, &m_textureMap[id]->width, &m_textureMap[id]->height);
return true;
}
return false;
}
void TextureManager::ClearFromTextureMap(std::string textureID)
{
m_textureMap.erase(textureID);
}
bool MenuState::onEnter()
{
if(!TextureManagerLoadFile("assets/Main menu/BTN PLAY.png", "play_button"))
{
return false;
}
if(!TextureManagerLoadFile("assets/Main menu/BTN Exit.png", "exit_button"))
//replace different png file here will also affect the outcome
{
return false;
}
if(!TextureManagerLoadFile("assets/Main menu/BTN SETTINGS.png", "setting_button"))
{
return false;
}
int client_w,client_h;
SDL_GetWindowSize(Game::Instance().GetClientWindow(),&client_w, &client_h);
int playBtn_w = TextureManager::Instance().GetTextureWidth("play_button");
int playBtn_h = TextureManager::Instance().GetTuextureHeight("play_button");
int center_x = (client_w - playBtn_w) / 2;
int center_y = (client_h - playBtn_h) / 2;
ParamsLoader pPlayParams(center_x, center_y, playBtn_w, playBtn_h, "play_button");
int settingBtn_w = TextureManager::Instance().GetTextureWidth("setting_button");
int settingBtn_h = TextureManager::Instance().GetTuextureHeight("setting_button");
ParamsLoader pSettingParams(center_x , center_y + (playBtn_h + settingBtn_h) / 2, settingBtn_w, settingBtn_h, "setting_button");
int exitBtn_w = TextureManager::Instance().GetTextureWidth("exit_button");
int exitBtn_h = TextureManager::Instance().GetTuextureHeight("exit_button");
ParamsLoader pExitParams(10, 10, exitBtn_w, exitBtn_h, "exit_button");
m_gameObjects.push_back(std::make_shared<MenuUIObject>(&pPlayParams, s_menuToPlay));
m_gameObjects.push_back(std::make_shared<MenuUIObject>(&pSettingParams, s_menuToPlay));
m_gameObjects.push_back(std::make_shared<MenuUIObject>(&pExitParams, s_menuExit));
//change order of the 3 line code above
//or replace different png for exit button, will make the rectangle color different
std::cout << "Entering Menu State" << std::endl;
return true;
}
bool MenuState::onExit()
{
for(auto i : m_gameObjects)
{
i->Clean();
}
m_gameObjects.clear();
TextureManager::Instance().ClearFromTextureMap("play_button");
TextureManager::Instance().ClearFromTextureMap("exit_button");
TextureManager::Instance().ClearFromTextureMap("setting_button");
std::cout << "Exiting Menu State" << std::endl;
return true;
}
void Game::Render()
{
SDL_SetRenderDrawColor(m_pRenderer, 255, 255, 255, 255);
SDL_RenderClear(m_pRenderer);
m_pGameStateMachine->Render();
SDL_RenderPresent(m_pRenderer);
}
Menu State Figure
Correct Color
Wrong Color
edit :Also, I found out that this weird phenomenon only happens when the renderer was created with 'SDL_RENDERER_ACCELERATED' flag and -1 or 0 driver index, i.e SDL_CreateRenderer(m_pWindow, 1, SDL_RENDERER_ACCELERATED); or SDL_CreateRenderer(m_pWindow, -1, SDL_RENDERER_SOFTWARE);works fine!
I have been plagued by this very same issue. The link provided by ekodes is how I resolved it, as order of operations had no effect for me.
I was able to pull the d3d9Device via SDL_RenderGetD3D9Device(), then SetTextureStageState as described in ekodes d3d blending link.
I was having the same issue. I got a vibrant green color when trying to render a light gray.
The combination of the parameters that are fixing the issue for you pertain to the driver to be used. -1 selects the first driver that meets the criteria, int this case it needs to be accelerated.
Using SDL_GetRendererInfo I was able to see this happens when using the "direct3d" driver.
I found this question talking about blending in direct3d.
I figured it out eventually. In addition to Alpha Blending there is a Color Blending. So DirectX merges color of the last texture with the last primitive.
The question does provide a fix for this in DirectX, however I'm not sure how to apply that it in regards to SDL. I also have not been able to find a solution for this problem in SDL.
I was drawing Green text with SDL_ttf, which uses a texture. Then drawing a gray rectangle for another component elsewhere on the screen.
What's strange is it doesn't seem to happen all the time. However, mine seems to predominantly happen with SDL_ttf. At first I thought it may be a byproduct of TTF_RenderText_Blended however, it happens with the other ones as well. It also does not appear to be affected by the blend mode of the Texture generated by those functions
So in my case, I was able to change the order of the operations to get the correct color.
Alternatively, using the OpenGL driver appeared to fix this as well. Similar to what you mentioned. (This was driver index 1 for me)
I'm not sure this classifies as an "Answer" but hopefully it helps someone out or points them in the right direction.
Im sure that it will be a simple and obvious fix, but I cannot see why this occurs.
Basically I want to code a button to change its background colour, depending on what the colour is at the present. The following code works but it uses the UI Colours in xcode.
-(IBAction)Button1Colour:(id)sender{
if (_Button1.backgroundColor == nil) {
_Button1.backgroundColor = [UIColor orangeColor];}
else if (_Button1.backgroundColor == [UIColor orangeColor]) {
_Button1.backgroundColor = [UIColor greenColor];}
else (_Button1.backgroundColor = nil);}
Now if I use RGB colours as follows:
-(IBAction)Button1Colour:(id)sender{
if (_Button1.backgroundColor == nil) {
_Button1.backgroundColor = [UIColor colorWithRed:(216/255.f) green:(146/255.f) blue:(48/255.f) alpha:0.3];}
else if (_Button1.backgroundColor == [UIColor colorWithRed:(216/255.f) green:(146/255.f) blue:(48/255.f) alpha:0.3]) {
_Button1.backgroundColor = [UIColor colorWithRed:(33/255.f) green:(141/255.f) blue:(8/255.f) alpha:0.3];}
else (_Button1.backgroundColor = nil);}
The button will only cycle from nil to amber to nil etc missing out the else if statement.
Any advice or help would be much appreciated
You're trying to determine whether the button is a particular color by comparing 3 sets of floating point numbers.
The second if test is failing because you can't compare CGFloats for exact equality.
The easier way is to subclass your button and add a BOOL property indicating whether it's "toggled" or not. Then you can check the property and simply change between one color and the next.
Assuming the property you add is called green, it would look like this
#property (assign, getter=isGreen) BOOL green;
and you could more concisely change the color like so
Button1.backgroundColor = [Button1 isGreen] ? [UIColor orangeColor] : [UIColor greenColor];
Button1.green = !Button1.green;
As an aside, naming conventions suggest that a class starts with a capital letter, e.g. UIButton. An instance variable starts with a lowercase letter, e.g. button1.
is there a way how to determine if the current mouse cursor is animated ?
I was looking for a way how to save the current cursor some time ago. I found the DrawIconEx function which perfectly suits to my purpose. Unfortunately I don't know how do I determine if the current cursor is animated. I was hoping that if I set the istepIfAniCur parameter to 1 in case of static cursor DrawIconEx returns False but it really ignores that parameter and returns True what disallows me to use it in the loop for getting the static cursor as well as all the frames from the animated one. In case of animated one works as expected so when you get out of range with istepIfAniCur it returns False.
So how do I find out that HICON (HCURSOR) is the animated cursor ? How the DrawIconEx determine that the cursor is animated ?
Thanks a lot
I've found one workaround - pass to the istepIfAniCur parameter of the DrawIconEx function max value of UINT. It's impossible that someone would create animated cursor with 4,294,967,295 frames (possible maybe for some cursor movie :)
With this fact you can pass this value to the DrawIconEx function which will return False in case when the cursor is animated (because of exceeding the frame range) and True in case of static one, because it ignores the istepIfAniCur parameter. You should pass 0 to the diFlags parameter because there's no need to draw anything.
Here's the Delphi example:
if not DrawIconEx(Canvas.Handle, 0, 0, hCursor, 0, 0, High(Cardinal), 0, 0) then
Caption := 'Cursor is animated ...'
else
Caption := 'Cursor is not animated ...';
And because I promised C++ tag here's my translation attempt
if (!DrawIconEx(this->Canvas->Handle, 0, 0, hCursor, 0, 0, UINT_MAX, NULL, 0))
this->Caption = "Cursor is animated ...";
else
this->Caption = "Cursor is not animated ...";
Exceeding the frame range is also indicated by the OS error ERROR_INVALID_PARAMETER what you may inspect using GetLastError function when the DrawIconEx fails.
Best way:
typedef HCURSOR(WINAPI* GET_CURSOR_FRAME_INFO)(HCURSOR, LPCWSTR, DWORD, DWORD*, DWORD*);
GET_CURSOR_FRAME_INFO fnGetCursorFrameInfo = 0;
HMODULE libUser32 = LoadLibraryA("user32.dll");
if (!libUser32)
{
return false;
}
fnGetCursorFrameInfo = reinterpret_cast<GET_CURSOR_FRAME_INFO>(GetProcAddress(libUser32, "GetCursorFrameInfo"));
if (!fnGetCursorFrameInfo)
{
return false;
}
DWORD displayRate, totalFrames;
fnGetCursorFrameInfo(hcursor, L"", 0, &displayRate, &totalFrames);
Here's the example in Delphi (and attempt to translation to C++) how I was trying to get the cursor dimensions using GetIconInfo function, but it doesn't work as I've expected. It always returns the width of one frame in case of animated cursor so it seems that GetIconInfo doesn't take care of the frames at all. Or am I wrong ?
procedure TForm1.Timer1Timer(Sender: TObject);
var
IconInfo: TIconInfo;
CursorInfo: TCursorInfo;
Bitmap: Windows.TBitmap;
begin
CursorInfo.cbSize := SizeOf(CursorInfo);
GetCursorInfo(CursorInfo);
GetIconInfo(CursorInfo.hCursor, IconInfo);
if GetObject(IconInfo.hbmColor, SizeOf(Bitmap), #Bitmap) <> 0 then
begin
Caption := 'Cursor size: ' +
IntToStr(Bitmap.bmWidth) + ' x ' +
IntToStr(Bitmap.bmHeight) + ' px';
end;
DeleteObject(IconInfo.hbmColor);
DeleteObject(IconInfo.hbmMask);
end;
My Visual C++ attempt (note that I don't know C++ and have no compiler :)
CString txt;
ICONINFO ii;
CURSORINFO ci;
BITMAP bitmap;
ci.cbSize = SizeOf(CURSORINFO);
GetCursorInfo(ci);
GetIconInfo(ci.hCursor, ii);
GetObject(ii.hbmColor, sizeof(BITMAP), &bitmap);
txt.Format("Cursor width: %d px", bitmap.bmWidth);
MessageBox(txt);
I'm attempting to solve what I thought would be a very simple problem. I want to keep a QPixmap updated with the entire screen contents. You can get such a pixmap by doing this:
QDesktopWidget *w = QApplication::desktop();
if (w)
{
QRect r = w->screenGeometry();
QPixmap p = QPixmap::grabWindow(w->winId(), 0, 0, r.width(), r.height())
QByteArray bitmap;
}
The problem with this is that QDesktopWidget ends up re-grabbing the entire screen pixmap from the X11 server every time you ask for it, even if nothing has changed.
I need this code to be fast, so I'm trying to do this myself. My starting point was the qx11mirror demo, however, that basically does the same thing. It uses the XDamage extension to work out when something has changed, but instead of using the damaged rectangle information to just update that part of the cached pixmap, it just sets a "dirty" flag, which triggers an entire refresh anyway.
So I'm trying to modify the qx11mirror example to just update the damaged portion of the windows, but I can't seem to get anything to work - all I get is a blank (black) pixmap. The code I'm using is:
void QX11Mirror::x11Event(XEvent *event)
{
if (event->type == m_damageEvent + XDamageNotify)
{
XDamageNotifyEvent *e = reinterpret_cast<XDamageNotifyEvent*>(event);
XWindowAttributes attr;
XGetWindowAttributes(QX11Info::display(), m_window, &attr);
XRenderPictFormat *format = XRenderFindVisualFormat(QX11Info::display(), attr.visual);
bool hasAlpha = ( format->type == PictTypeDirect && format->direct.alphaMask );
int x = attr.x;
int y = attr.y;
int width = attr.width;
int height = attr.height;
// debug output so I can see the window pos vs the damaged area:
qDebug() << "repainting dirty area:" << x << y << width << height << "vs" << e->area.x << e->area.y << e->area.width << e->area.height;
XRenderPictureAttributes pa;
pa.subwindow_mode = IncludeInferiors; // Don't clip child widgets
Picture picture = XRenderCreatePicture(QX11Info::display(),
m_window,
format,
CPSubwindowMode,
&pa);
XserverRegion region = XFixesCreateRegionFromWindow(QX11Info::display(),
m_window, WindowRegionBounding);
XFixesTranslateRegion(QX11Info::display(), region, -x, -y);
XFixesSetPictureClipRegion(QX11Info::display(), picture, 0, 0, region);
XFixesDestroyRegion(QX11Info::display(), region);
//QPixmap dest(width, height);
XRenderComposite(QX11Info::display(), // display
hasAlpha ? PictOpOver : PictOpSrc, // operation mode
picture, // src drawable
None, // src mask
dest.x11PictureHandle(), // dest drawable
e->area.x, // src X
e->area.y, // src Y
0, // mask X
0, // mask Y
e->area.x, // dest X
e->area.y, // dest Y
e->area.width, // width
e->area.height); // height
m_px = dest;
XDamageSubtract(QX11Info::display(), e->damage, None, None);
emit windowChanged();
}
else if (event->type == ConfigureNotify)
{
XConfigureEvent *e = &event->xconfigure;
m_position = QRect(e->x, e->y, e->width, e->height);
emit positionChanged(m_position);
}
}
Can anyone point me in the right direction? The documetnation for XRender, XDamage, and the other X11 extensions is pretty bad.
Reasons for using XRender over XCopyArea
The following text taken from here.
It is perfectly possible to create a GC for a window and use XCopyArea() to copy the contents of the window if you want to use the core protocol, but since the Composite extension exposes new visuals (ones with alpha channels e.g.), there's no guarantee that the format of the source drawable will match that of the destination. With the core protocol that situation will result in a match error, something that won't happen with the Xrender extension.
In addition the core protocol has no understanding of alpha channels, which means that it can't composite windows that use the new ARGB visual. When the source and destination have the same format, there's also no performance advantage to using the core protocol as of X11R6.8. That release is also the first to support the new Composite extension.
So in conclusion there are no drawbacks, and only advantages to choosing Xrender over the core protocol for these operations.
First you need to change the DamageReportLevel in the call to DamageCreate in QX11Mirror::setWindow from DamageReportNotEmpty to XDamageReportBoundingBox.
Next you need to call dest.detach() before the call to XRenderComposite. You don't really need both m_px and dest as member variables though - you can just use m__px.
There is also a missing call to XRenderFreePicture in that example which should go after the call to XRenderComposite:
XRenderFreePicture(QX11Info::display(), picture);
You don't need to duplicate all the code QX11Mirror::pixmap in QX11Mirror::x11Event. Instead change the type of m_dirty from bool to QRect, then have x11Event update m_dirty with the rectangle from the XDamageNotifyEvent,i.e. e->area. Then in QX11Mirror:pixmap rather than checking if m_dirty is true, check if m_dirty is not an empty rectangle. You would then pass the rectangle from m_dirty to XRenderComposite.
Edit:
The dest.detach is the key bit - without that you'll never get it to work.
I have a check box that I want to accurately measure so I can position controls on a dialog correctly. I can easily measure the size of the text on the control - but I don't know the "official" way of calculating the size of the check box and the gap before (or after) the text.
I'm pretty sure the width of the checkbox is equal to
int x = GetSystemMetrics( SM_CXMENUCHECK );
int y = GetSystemMetrics( SM_CYMENUCHECK );
You can then work out the area inside by subtracting the following ...
int xInner = GetSystemMetrics( SM_CXEDGE );
int yInner = GetSystemMetrics( SM_CYEDGE );
I use that in my code and haven't had a problem thus far ...
Short answer:
Long Version
From MSDN Layout Specifications: Win32, we have the specifications of the dimensions of a checkbox.
It is 12 dialog units from the left edge of the control to the start of the text:
And a checkbox control is 10 dialog units tall:
Surfaces and Controls Height (DLUs) Width (DLUs)
===================== ============= ===========
Check box 10 As wide as possible (usually to the margins) to accommodate localization requirements.
First we calculate the size of a horizontal and a vertical dialog unit:
const dluCheckBoxInternalSpacing = 12; //12 horizontal dlus
const dluCheckboxHeight = 10; //10 vertical dlus
Size dialogUnits = GetAveCharSize(dc);
Integer checkboxSpacing = MulDiv(dluCheckboxSpacing, dialogUnits.Width, 4);
Integer checkboxHeight = MulDiv(dluCheckboxHeight, dialogUnits.Height, 8);
Using the handy helper function:
Size GetAveCharSize(HDC dc)
{
/*
How To Calculate Dialog Base Units with Non-System-Based Font
http://support.microsoft.com/kb/125681
*/
TEXTMETRIC tm;
GetTextMetrics(dc, ref tm);
String buffer = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz";
Size result;
GetTextExtentPoint32(dc, buffer, 52, out result);
result.Width = (result.X/26 + 1) / 2; //div uses trunc rounding; we want arithmetic rounding
result.Height = tm.tmHeight;
return result;
}
Now that we know how many pixels (checkboxSpacing) to add, we calculate the label size as normal:
textRect = Rect(0,0,0,0);
DrawText(dc, Caption, -1, textRect, DT_CALCRECT or DT_LEFT or DT_SINGLELINE);
chkVerification.Width = checkboxSpacing+textRect.Right;
chkVerification.Height = checkboxHeight;
Bonus Reading
What's a dialog unit?
A dialog is a unit of measure based on the user's preferred font size. A dialog unit is defined such that the average character is 4 dialog units wide by 8 dialog units high:
This means that dialog units:
change with selected font
changed with selected DPI setting
are not square
Note: Any code released into public domain. No attribution required.
Sorry for resurrecting this old thread. I recently found myself wondering about the exact same question. Currently, none of the answers above give a result consistent with Windows 10 for different fonts and font sizes, especially in high-DPI environments.
Instead, it seems that the correct result is obtained by
SIZE szCheckBox;
GetThemePartSize(hTheme, hDC, BP_CHECKBOX, CBS_UNCHECKEDNORMAL, &rcBackgroundContent, TS_TRUE, &szCheckBox);
for the size of the checkbox itself. And
SIZE szZeroCharacter;
GetTextExtentPoint32(hDC, L"0", 1, &szZeroCharacter);
int iGapWidth = szZeroCharacter.cx / 2;
for the width of the gap. After trying a lot of different methods inspired by the posts above, I found L"0" in the dissembly of comctl32.dll. And while it looks like a joke to me (not necessarily a good one), I suspect it's a holdover from the old days when this might have been a good enough approximation of 2DLU.
Disclaimer: While I tested the result with various fonts and different sizes on Windows 10, I have not attempted to verify that it also holds on any other (older) version of the operating system.
It is a shame that Microsoft did not provide a way to know this for sure. I was struggling with the same question and the answer provided above is not complete. The main problem with it is that if the font of the dialog window is set to something other than the default size, that solution will not work because checkboxes will be resized.
Here's how I solved this issue (it is just an approximation that seems to have worked for me). The code is for MFC project.
1 - Create two test controls on your form, a checkbox and a radio box:
2 - Define the following custom struct:
struct CHECKBOX_DIMS{
int nWidthPx;
int nHeightPx;
int nSpacePx; //Space between checkbox and text
CHECKBOX_DIMS()
{
nWidthPx = 0;
nHeightPx = 0;
nSpacePx = 0;
}
};
3 - Call the following code when form initializes for each of the test controls (that will measure them and remove them so that end-users don't seem them):
BOOL OnInitDialog()
{
CDialog::OnInitDialog();
//Calculate the size of a checkbox & radio box
VERIFY(GetInitialCheckBoxSize(IDC_CHECK_TEST, &dimsCheckBox, TRUE));
VERIFY(GetInitialCheckBoxSize(IDC_RADIO_TEST, &dimsRadioBox, TRUE));
//Continue with form initialization ...
}
BOOL GetInitialCheckBoxSize(UINT nCtrlID, CHECKBOX_DIMS* pOutCD, BOOL bRemoveCtrl)
{
//Must be called initially to calculate the size of a checkbox/radiobox
//'nCtrlID' = control ID to measure
//'pOutCD' = if not NULL, receives the dimensitions
//'bRemoveCtrl' = TRUE to delete control
//RETURN:
// = TRUE if success
BOOL bRes = FALSE;
//Get size of a check (not exactly what we need)
int nCheckW = GetSystemMetrics(SM_CXMENUCHECK);
int nCheckH = GetSystemMetrics(SM_CYMENUCHECK);
//3D border spacer (not exactly what we need either)
int nSpacerW = GetSystemMetrics(SM_CXEDGE);
//Get test checkbox
CButton* pChkWnd = (CButton*)GetDlgItem(nCtrlID);
ASSERT(pChkWnd);
if(pChkWnd)
{
CRect rcCheckBx;
pChkWnd->GetWindowRect(&rcCheckBx);
//We need only the height
//INFO: The reason why we can't use the width is because there's
// an arbitrary text followed by a spacer...
int h = rcCheckBx.Height();
CDC* pDc = pChkWnd->GetDC();
if(pDc)
{
//Get horizontal DPI setting
int dpiX = pDc->GetDeviceCaps(LOGPIXELSX);
//Calculate
if(pOutCD)
{
//Use height as-is
pOutCD->nHeightPx = h;
//Use height for the width
pOutCD->nWidthPx = (int)(h * ((double)nCheckW / nCheckH));
//Spacer is the hardest
//INFO: Assume twice and a half the size of 3D border &
// take into account DPI setting for the window
// (It will give some extra space, but it's better than less space.)
// (This number is purely experimental.)
// (96 is Windows DPI setting for 100% resolution setting.)
pOutCD->nSpacePx = (int)(nSpacerW * 2.5 * dpiX / 96.0);
}
//Release DC
pChkWnd->ReleaseDC(pDc);
if(bRemoveCtrl)
{
//Delete window
bRes = pChkWnd->DestroyWindow();
}
else
{
//Keep the window
bRes = TRUE;
}
}
}
return bRes;
}
4 - Now you can easily resize any checkbox or radio box by calling this:
//Set checkbox size & new text
VERIFY(SetCheckBoxTextAndSize(this, IDC_CHECK_ID, &dimsCheckBox, L"New text") > 0);
//Just resize radio box
VERIFY(SetCheckBoxTextAndSize(this, IDC_RADIO_ID, &dimsRadioBox, NULL) > 0);
int SetCheckBoxTextAndSize(CWnd* pParWnd, UINT nCheckBoxID, CHECKBOX_DIMS* pDims, LPCTSTR pNewText)
{
//Set size of the checkbox/radio to 'pNewText' and update its size according to its text
//'pParWnd' = parent dialog window
//'nCheckBoxID' = control ID to resize (checkbox or radio box)
//'pDims' = pointer to the struct with checkbox/radiobox dimensions
//'pNewText' = text to set, or NULL not to change the text
//RETURN:
// = New width of the control in pixels, or
// = 0 if error
int nRes = 0;
ASSERT(pParWnd);
ASSERT(pDims);
CButton* pChkWnd = (CButton*)pParWnd->GetDlgItem(nCheckBoxID);
ASSERT(pChkWnd);
if(pChkWnd)
{
CDC* pDc = pChkWnd->GetDC();
CFont* pFont = pChkWnd->GetFont();
if(pDc)
{
if(pFont)
{
//Make logfont
LOGFONT lf = {0};
if(pFont->GetLogFont(&lf))
{
//Make new font
CFont font;
if(font.CreateFontIndirect(&lf))
{
//Get font from control
CFont* pOldFont = pDc->SelectObject(&font);
//Get text to set
CString strCheck;
if(pNewText)
{
//Use new text
strCheck = pNewText;
}
else
{
//Keep old text
pChkWnd->GetWindowText(strCheck);
}
//Calculate size
RECT rc = {0, 0, 0, 0};
::DrawText(pDc->GetSafeHdc(), strCheck, strCheck.GetLength(), &rc, DT_CALCRECT | DT_NOPREFIX | DT_SINGLELINE);
//Get text width
int nTextWidth = abs(rc.right - rc.left);
//See if it's valid
if(nTextWidth > 0 ||
(nTextWidth == 0 && strCheck.GetLength() == 0))
{
//Get location of checkbox
CRect rcChk;
pChkWnd->GetWindowRect(&rcChk);
pParWnd->ScreenToClient(rcChk);
//Update its size
rcChk.right = rcChk.left + pDims->nWidthPx + pDims->nSpacePx + nTextWidth;
//Use this line if you want to change the height as well
//rcChk.bottom = rcChk.top + pDims->nHeightPx;
//Move the control
pChkWnd->MoveWindow(rcChk);
//Setting new text?
if(pNewText)
{
pChkWnd->SetWindowText(pNewText);
}
//Done
nRes = abs(rcChk.right - rcChk.left);
}
//Set font back
pDc->SelectObject(pOldFont);
}
}
}
//Release DC
pChkWnd->ReleaseDC(pDc);
}
}
return nRes;
}
I'd like to give my 2 cents on the matter since iv spent an entire day working on an accurate solution for this problem that takes DPI awareness and fonts into consideration.
First define the checkbox's size in units.
#define CHECKBOX_INTERNAL_SIZE 12
Then i defined a function for converting units to pixels. NOTE: MulDiv may work just as good.
double dpi_MulDiv(double nNumber, double nNumerator, double nDenominator)
{
return (nNumber * nNumerator) / nDenominator;
}
Finally the function that does the magic. SEE the code comments for details.
//
// Get the minimum size of the Checkbox.
// NOTE: The font of the control must be set before calling this function.
//
SIZE dpi_GetCheckBoxWidth(HWND hWnd, int monitorDpi)
{
HDC dc;
HFONT hFont;
HFONT oldFont;
TEXTMETRIC tm;
double checkboxSize;
double whiteSpace;
WCHAR sourceString[128];
RECT txtRect;
SIZE size;
dc = GetDC(hWnd);
// Note that GetDC returns an uninitialized DC, which has "System" (a bitmap font) as the default font; thus the need to select a font into the DC.
hFont = (HFONT)SendMessage(hWnd, WM_GETFONT, 0, 0);
oldFont = (HFONT)SelectObject(dc, hFont);
// Get the Checkbox width.
checkboxSize = round(dpi_MulDiv(CHECKBOX_INTERNAL_SIZE, monitorDpi, 96));
// Get the space between the Checkbox and text.
GetTextMetrics(dc, &tm);
whiteSpace = round((double)tm.tmAveCharWidth / 2.0f);
// Get the Text width.
txtRect = { 0, 0, 0, 0 };
if (GetWindowTextW(hWnd, sourceString, 128) != 0)
{
DrawTextW(dc, sourceString, -1, &txtRect, DT_CALCRECT | DT_LEFT | DT_SINGLELINE);
}
// Cleanup.
SelectObject(dc, oldFont);
ReleaseDC(hWnd, dc);
// Done.
size.cx = (LONG)checkboxSize + (LONG)whiteSpace + txtRect.right + 3;
size.cy = ((LONG)checkboxSize < txtRect.bottom) ? txtRect.bottom : (LONG)checkboxSize;
return size;
}
I added + 3 on the last line that computes the width as a way to adjust for little irregularities. Feed back on this is welcomed. Iv only tested on Windows 10 thus far with different fonts and sizes.
This code doesn't work on Win7 with scaled UI (fonts 125% larger or 150% larger). The only thing that seems to work is:
int WID = 13 * dc.GetDeviceCaps(LOGPIXELSX) / 96;
int HEI = 13 * dc.GetDeviceCaps(LOGPIXELSY) / 96;
Ok dudes my way is maybe not the fastes to use in runtime, but it works for me in any case i have tested so far.
In the beginnin of my proggys i put in a function to get the size and store it in a global variable (yeah i have heard this would be bad, but i dont care about this)
here the explanation:
Create a treeview (invisible if u want)
Create an imagelist with atleast 1 image inside (size 16x16)
Set the imagelist to the treeview ("TVSIL_NORMAL")
Get the "TVSIL_STATE" imagelist from the treeview (u have to create "TVSIL_NORMAL" before, otherwise this one will fail!)
Use ImageList_GetIconSize(..) and store the size. Wow, the checkboxs and the radio-buttons have the same size as the state icons of the treeview. Now u have what u want!
Destroy the "TVSIL_NORMAL" imagelist
Destroy the treeview
this code needs only a few microseconds at the beginning of my proggies and i can use the value everytime i need it.
Preamble:
I had the same question while trying to determine the needed size of the checkbox control for a given text and found that the existing answers didn't really work for me, for several reasons:
SM_CXMENUCHECK doesn't account for the gap. In fact, I'm not convinced this is even for regular checkboxes, although it may have the same value. It may also be dependent on visual styles being enabled.
The other answers were overly complicated and felt a bit hacky (no disrespect intended, it is MS that don't make this easy).
The stated 12DLU layout was very helpful, although again feels arbitrary without a system metric to rely on.
The answers I tried still didn't yield a high enough pixel value to stop the checkbox text from wrapping.
My investigation:
I looked at how Wine reproduces the behavior and found that it also gives the same results as simply assuming 12DLU. However, the text still wrapped unless I added an extra 3 pixels to the width (even though the text should fit fine without). I also noticed that GetTextExtentPoint32 yields a value of 3 for an empty string (hmmm...)
Turning off the BS_MULTILINE style obviously stopped the text wrapping. My guess is that DrawTextW's word wrapping calculations are imperfect.
At this point I decided that the simplest solution was to just add 1 extra space to GetTextExtentPoint32, so that there would definitely be enough pixels. The over-estimate of a couple of pixels was acceptable to me.
Note that this all assumes your application is manifested as DPI aware. Otherwise I found the checkbox appeared much larger on some Windows 7 systems (not all though).
My (mostly Wine's) solution:
// This code gets the size of a piece of text and adds the size of a
// checkbox and gap. Note that this is very rough code with no error handling.
BOOL isCheckbox = TRUE;
HWND dialog = ... // Your control or dialog
HFONT font = ... // The font your control will use if it hasn't been set yet
PTCHAR text = ... // Your text
HFONT currentFont;
SIZE size;
HDC dc = GetDC(dialog);
if (!font) {
font = (HFONT)SendMessage(dialog, WM_GETFONT, 0, 0);
}
currentFont = (HFONT)SelectObject(dc, font); // NB: You should add error handling here
if (isCheckbox) {
// Or you can disable BS_MULTILINE
_tcscat(text, TEXT(" ")); // NB: This assumes text is allocated for +1 char
}
GetTextExtentPoint32(dc, text, _tcslen(text), &size); // NB: You should add error handling here
if (isCheckbox) {
int checkBoxWidth = 12 * GetDeviceCaps(dc, LOGPIXELSX ) / 96 + 1;
int checkBoxHeight = 12 * GetDeviceCaps(dc, LOGPIXELSY ) / 96 + 1;
int textOffset;
GetCharWidthW(dc, '0', '0', &textOffset);
textOffset /= 2;
size->cx += checkBoxWidth + textOffset;
if (size->cy < checkBoxHeight) {
size->cy = checkBoxHeight;
}
}
if (currentFont) {
SelectObject(dc, currentFont);
}
ReleaseDC(dialog, dc);