/// GetTextMargins - checks to see if we have cached information about the current font,
/// returns info about it.
/// An MRU of Font margins was considered, but seems like overhead.
internal static User32.DRAWTEXTPARAMS GetTextMargins(WindowsGraphics wg, WindowsFont font)
{
// PERF: operate on a local reference rather than party directly on the thread static one.
CachedInfo currentCachedInfo = cachedMeasurementDCInfo;
if (currentCachedInfo != null && currentCachedInfo.LeftTextMargin > 0 && currentCachedInfo.RightTextMargin > 0 && font == currentCachedInfo.LastUsedFont)
{
// we have to return clones as DrawTextEx will modify this struct
return(new User32.DRAWTEXTPARAMS
{
iLeftMargin = currentCachedInfo.LeftTextMargin,
iRightMargin = currentCachedInfo.RightTextMargin
});
}
else if (currentCachedInfo == null)
{
currentCachedInfo = new CachedInfo();
cachedMeasurementDCInfo = currentCachedInfo;
}
User32.DRAWTEXTPARAMS drawTextParams = wg.GetTextMargins(font);
currentCachedInfo.LeftTextMargin = drawTextParams.iLeftMargin;
currentCachedInfo.RightTextMargin = drawTextParams.iRightMargin;
// returning a copy here to be consistent with the return value from the cache.
return(new User32.DRAWTEXTPARAMS
{
iLeftMargin = currentCachedInfo.LeftTextMargin,
iRightMargin = currentCachedInfo.RightTextMargin
});
}
internal static IntNativeMethods.DRAWTEXTPARAMS GetTextMargins(WindowsGraphics wg, WindowsFont font)
{
CachedInfo cachedMeasurementDCInfo = MeasurementDCInfo.cachedMeasurementDCInfo;
if (((cachedMeasurementDCInfo == null) || (cachedMeasurementDCInfo.LeftTextMargin <= 0)) || ((cachedMeasurementDCInfo.RightTextMargin <= 0) || (font != cachedMeasurementDCInfo.LastUsedFont)))
{
if (cachedMeasurementDCInfo == null)
{
cachedMeasurementDCInfo = new CachedInfo();
MeasurementDCInfo.cachedMeasurementDCInfo = cachedMeasurementDCInfo;
}
IntNativeMethods.DRAWTEXTPARAMS textMargins = wg.GetTextMargins(font);
cachedMeasurementDCInfo.LeftTextMargin = textMargins.iLeftMargin;
cachedMeasurementDCInfo.RightTextMargin = textMargins.iRightMargin;
}
return new IntNativeMethods.DRAWTEXTPARAMS(cachedMeasurementDCInfo.LeftTextMargin, cachedMeasurementDCInfo.RightTextMargin);
}
internal static IntNativeMethods.DRAWTEXTPARAMS GetTextMargins(WindowsGraphics wg, WindowsFont font)
{
CachedInfo cachedMeasurementDCInfo = MeasurementDCInfo.cachedMeasurementDCInfo;
if (((cachedMeasurementDCInfo == null) || (cachedMeasurementDCInfo.LeftTextMargin <= 0)) || ((cachedMeasurementDCInfo.RightTextMargin <= 0) || (font != cachedMeasurementDCInfo.LastUsedFont)))
{
if (cachedMeasurementDCInfo == null)
{
cachedMeasurementDCInfo = new CachedInfo();
MeasurementDCInfo.cachedMeasurementDCInfo = cachedMeasurementDCInfo;
}
IntNativeMethods.DRAWTEXTPARAMS textMargins = wg.GetTextMargins(font);
cachedMeasurementDCInfo.LeftTextMargin = textMargins.iLeftMargin;
cachedMeasurementDCInfo.RightTextMargin = textMargins.iRightMargin;
}
return(new IntNativeMethods.DRAWTEXTPARAMS(cachedMeasurementDCInfo.LeftTextMargin, cachedMeasurementDCInfo.RightTextMargin));
}