Code:
/ DotNET / DotNET / 8.0 / untmp / whidbey / REDBITS / ndp / fx / src / WinForms / Managed / System / WinForms / Layout / LayoutUtils.cs / 1 / LayoutUtils.cs
//------------------------------------------------------------------------------
//
// Copyright (c) Microsoft Corporation. All rights reserved.
//
//-----------------------------------------------------------------------------
namespace System.Windows.Forms.Layout {
using System;
using System.Collections;
using System.Diagnostics;
using System.Drawing;
using System.Windows.Forms.Internal;
using System.Drawing.Text;
using System.Runtime.InteropServices;
using System.Windows.Forms;
using System.Windows.Forms.ComponentModel;
using System.Collections.Generic;
// Utilities used by layout code. If you use these outside of the layout
// namespace, you should probably move them to WindowsFormsUtils.
internal class LayoutUtils {
public static readonly Size MaxSize = new Size(Int32.MaxValue, Int32.MaxValue);
public static readonly Size InvalidSize = new Size(Int32.MinValue, Int32.MinValue);
public static readonly Rectangle MaxRectangle = new Rectangle(0, 0, Int32.MaxValue, Int32.MaxValue);
public const ContentAlignment AnyTop = ContentAlignment.TopLeft | ContentAlignment.TopCenter | ContentAlignment.TopRight;
public const ContentAlignment AnyBottom = ContentAlignment.BottomLeft | ContentAlignment.BottomCenter | ContentAlignment.BottomRight;
public const ContentAlignment AnyLeft = ContentAlignment.TopLeft | ContentAlignment.MiddleLeft | ContentAlignment.BottomLeft;
public const ContentAlignment AnyRight = ContentAlignment.TopRight | ContentAlignment.MiddleRight | ContentAlignment.BottomRight;
public const ContentAlignment AnyCenter = ContentAlignment.TopCenter | ContentAlignment.MiddleCenter | ContentAlignment.BottomCenter;
public const ContentAlignment AnyMiddle = ContentAlignment.MiddleLeft | ContentAlignment.MiddleCenter | ContentAlignment.MiddleRight;
public const AnchorStyles HorizontalAnchorStyles = AnchorStyles.Left | AnchorStyles.Right;
public const AnchorStyles VerticalAnchorStyles = AnchorStyles.Top | AnchorStyles.Bottom;
private static readonly AnchorStyles[] dockingToAnchor = new AnchorStyles[] {
/* None */ AnchorStyles.Top | AnchorStyles.Left,
/* Top */ AnchorStyles.Top | AnchorStyles.Left | AnchorStyles.Right,
/* Bottom */ AnchorStyles.Bottom | AnchorStyles.Left | AnchorStyles.Right,
/* Left */ AnchorStyles.Left | AnchorStyles.Top | AnchorStyles.Bottom,
/* Right */ AnchorStyles.Right | AnchorStyles.Top | AnchorStyles.Bottom,
/* Fill */ AnchorStyles.Right | AnchorStyles.Top | AnchorStyles.Bottom | AnchorStyles.Left
};
// A good, short test string for measuring control height.
public readonly static string TestString = "j^";
// Returns the size of the largest string in the given collection. Non-string objects are converted
// with ToString(). Uses OldMeasureString, not GDI+. Does not support multiline.
public static Size OldGetLargestStringSizeInCollection(Font font, ICollection objects) {
Size largestSize = Size.Empty;
if (objects != null) {
foreach(object obj in objects) {
Size textSize = TextRenderer.MeasureText(obj.ToString(), font, new Size(Int16.MaxValue, Int16.MaxValue), TextFormatFlags.SingleLine);
largestSize.Width = Math.Max(largestSize.Width, textSize.Width);
largestSize.Height = Math.Max(largestSize.Height, textSize.Height);
}
}
return largestSize;
}
/*
* We can cut ContentAlignment from a max index of 1024 (12b) down to 11 (4b) through
* bit twiddling. The int result of this function maps to the ContentAlignment as indicated
* by the table below:
*
* Left Center Right
* Top 0000 0x0 0001 0x1 0010 0x2
* Middle 0100 0x4 0101 0x5 0110 0x6
* Bottom 1000 0x8 1001 0x9 1010 0xA
*
* (The high 2 bits determine T/M/B. The low 2 bits determine L/C/R.)
*/
public static int ContentAlignmentToIndex(ContentAlignment alignment) {
/*
* Here is what content alignment looks like coming in:
*
* Left Center Right
* Top 0x001 0x002 0x004
* Middle 0x010 0x020 0x040
* Bottom 0x100 0x200 0x400
*
* (L/C/R determined bit 1,2,4. T/M/B determined by 4 bit shift.)
*/
int topBits = xContentAlignmentToIndex(((int)alignment) & 0x0F);
int middleBits = xContentAlignmentToIndex(((int)alignment >> 4) & 0x0F);
int bottomBits = xContentAlignmentToIndex(((int)alignment >> 8) & 0x0F);
Debug.Assert((topBits != 0 && (middleBits == 0 && bottomBits == 0))
|| (middleBits != 0 && (topBits == 0 && bottomBits == 0))
|| (bottomBits != 0 && (topBits == 0 && middleBits == 0)),
"One (and only one) of topBits, middleBits, or bottomBits should be non-zero.");
int result = (middleBits != 0 ? 0x04 : 0) | (bottomBits != 0 ? 0x08 : 0) | topBits | middleBits | bottomBits;
// zero isn't used, so we can subtract 1 and start with index 0.
result --;
Debug.Assert(result >= 0x00 && result <=0x0A, "ContentAlignmentToIndex result out of range.");
Debug.Assert(result != 0x00 || alignment == ContentAlignment.TopLeft, "Error detected in ContentAlignmentToIndex.");
Debug.Assert(result != 0x01 || alignment == ContentAlignment.TopCenter, "Error detected in ContentAlignmentToIndex.");
Debug.Assert(result != 0x02 || alignment == ContentAlignment.TopRight, "Error detected in ContentAlignmentToIndex.");
Debug.Assert(result != 0x03, "Error detected in ContentAlignmentToIndex.");
Debug.Assert(result != 0x04 || alignment == ContentAlignment.MiddleLeft, "Error detected in ContentAlignmentToIndex.");
Debug.Assert(result != 0x05 || alignment == ContentAlignment.MiddleCenter, "Error detected in ContentAlignmentToIndex.");
Debug.Assert(result != 0x06 || alignment == ContentAlignment.MiddleRight, "Error detected in ContentAlignmentToIndex.");
Debug.Assert(result != 0x07, "Error detected in ContentAlignmentToIndex.");
Debug.Assert(result != 0x08 || alignment == ContentAlignment.BottomLeft, "Error detected in ContentAlignmentToIndex.");
Debug.Assert(result != 0x09 || alignment == ContentAlignment.BottomCenter, "Error detected in ContentAlignmentToIndex.");
Debug.Assert(result != 0x0A || alignment == ContentAlignment.BottomRight, "Error detected in ContentAlignmentToIndex.");
return result;
}
// Converts 0x00, 0x01, 0x02, 0x04 (3b flag) to 0, 1, 2, 3 (2b index)
private static byte xContentAlignmentToIndex(int threeBitFlag) {
Debug.Assert(threeBitFlag >= 0x00 && threeBitFlag <= 0x04 && threeBitFlag != 0x03, "threeBitFlag out of range.");
byte result = threeBitFlag == 0x04 ? (byte) 3 : (byte) threeBitFlag;
Debug.Assert((result & 0x03) == result, "Result out of range.");
return result;
}
public static Size ConvertZeroToUnbounded(Size size) {
if(size.Width == 0) size.Width = Int32.MaxValue;
if(size.Height == 0) size.Height = Int32.MaxValue;
return size;
}
// Clamps negative values in Padding struct to zero.
public static Padding ClampNegativePaddingToZero(Padding padding) {
// Careful: Setting the LRTB properties causes Padding.All to be -1 even if LRTB all agree.
if(padding.All < 0) {
padding.Left = Math.Max(0, padding.Left);
padding.Top = Math.Max(0, padding.Top);
padding.Right = Math.Max(0, padding.Right);
padding.Bottom = Math.Max(0, padding.Bottom);
}
return padding;
}
/*
* Maps an anchor to its opposite. Does not support combinations. None returns none.
*
* Top = 0x01
* Bottom = 0x02
* Left = 0x04
* Right = 0x08
*/
// Returns the positive opposite of the given anchor (e.g., L -> R, LT -> RB, LTR -> LBR, etc.). None return none.
private static AnchorStyles GetOppositeAnchor(AnchorStyles anchor) {
AnchorStyles result = AnchorStyles.None;
if (anchor == AnchorStyles.None){
return result;
}
// iterate through T,B,L,R
// bitwise or B,T,R,L as appropriate
for (int i = 1; i <= (int)AnchorStyles.Right; i=i <<1) {
switch (anchor & (AnchorStyles)i) {
case AnchorStyles.None:
break;
case AnchorStyles.Left:
result |= AnchorStyles.Right;
break;
case AnchorStyles.Top:
result |= AnchorStyles.Bottom;
break;
case AnchorStyles.Right:
result |= AnchorStyles.Left;
break;
case AnchorStyles.Bottom:
result |= AnchorStyles.Top;
break;
default:
break;
}
}
return result;
}
public static TextImageRelation GetOppositeTextImageRelation(TextImageRelation relation) {
return (TextImageRelation) GetOppositeAnchor((AnchorStyles)relation);
}
public static Size UnionSizes(Size a, Size b) {
return new Size(
Math.Max(a.Width, b.Width),
Math.Max(a.Height, b.Height));
}
public static Size IntersectSizes(Size a, Size b) {
return new Size(
Math.Min(a.Width, b.Width),
Math.Min(a.Height, b.Height));
}
public static bool IsIntersectHorizontally(Rectangle rect1, Rectangle rect2) {
if (!rect1.IntersectsWith(rect2)) {
return false;
}
if (rect1.X <= rect2.X && rect1.X + rect1.Width >= rect2.X + rect2.Width) {
//rect 1 contains rect 2 horizontally
return true;
}
if (rect2.X <= rect1.X && rect2.X + rect2.Width >= rect1.X + rect1.Width) {
//rect 2 contains rect 1 horizontally
return true;
}
return false;
}
public static bool IsIntersectVertically(Rectangle rect1, Rectangle rect2) {
if (!rect1.IntersectsWith(rect2)) {
return false;
}
if (rect1.Y <= rect2.Y && rect1.Y + rect1.Width >= rect2.Y + rect2.Width) {
//rect 1 contains rect 2 vertically
return true;
}
if (rect2.Y <= rect1.Y && rect2.Y + rect2.Width >= rect1.Y + rect1.Width) {
//rect 2 contains rect 1 vertically
return true;
}
return false;
}
//returns anchorStyles, transforms from DockStyle if necessary
internal static AnchorStyles GetUnifiedAnchor(IArrangedElement element) {
DockStyle dockStyle = DefaultLayout.GetDock(element);
if (dockStyle != DockStyle.None) {
return dockingToAnchor[(int)dockStyle];
}
return DefaultLayout.GetAnchor(element);
}
public static Rectangle AlignAndStretch(Size fitThis, Rectangle withinThis, AnchorStyles anchorStyles) {
return Align(Stretch(fitThis, withinThis.Size, anchorStyles), withinThis, anchorStyles);
}
public static Rectangle Align(Size alignThis, Rectangle withinThis, AnchorStyles anchorStyles) {
return VAlign(alignThis, HAlign(alignThis, withinThis, anchorStyles), anchorStyles);
}
public static Rectangle Align(Size alignThis, Rectangle withinThis, ContentAlignment align) {
return VAlign(alignThis, HAlign(alignThis, withinThis, align), align);
}
public static Rectangle HAlign(Size alignThis, Rectangle withinThis, AnchorStyles anchorStyles) {
if ((anchorStyles & AnchorStyles.Right) != 0) {
withinThis.X += withinThis.Width - alignThis.Width;
}
else if (anchorStyles == AnchorStyles.None || (anchorStyles & HorizontalAnchorStyles) == 0) {
withinThis.X += (withinThis.Width - alignThis.Width) / 2;
}
withinThis.Width = alignThis.Width;
return withinThis;
}
private static Rectangle HAlign(Size alignThis, Rectangle withinThis, ContentAlignment align) {
if ((align & AnyRight) != 0) {
withinThis.X += withinThis.Width - alignThis.Width;
}
else if ((align & AnyCenter) != 0) {
withinThis.X += (withinThis.Width - alignThis.Width) / 2;
}
withinThis.Width = alignThis.Width;
return withinThis;
}
public static Rectangle VAlign(Size alignThis, Rectangle withinThis, AnchorStyles anchorStyles) {
if ((anchorStyles & AnchorStyles.Bottom) != 0) {
withinThis.Y += withinThis.Height - alignThis.Height;
}
else if (anchorStyles == AnchorStyles.None || (anchorStyles & VerticalAnchorStyles) == 0) {
withinThis.Y += (withinThis.Height - alignThis.Height) / 2;
}
withinThis.Height = alignThis.Height;
return withinThis;
}
public static Rectangle VAlign(Size alignThis, Rectangle withinThis, ContentAlignment align) {
if ((align & AnyBottom) != 0) {
withinThis.Y += withinThis.Height - alignThis.Height;
}
else if ((align & AnyMiddle) != 0) {
withinThis.Y += (withinThis.Height - alignThis.Height) / 2;
}
withinThis.Height = alignThis.Height;
return withinThis;
}
public static Size Stretch(Size stretchThis, Size withinThis, AnchorStyles anchorStyles) {
Size stretchedSize = new Size(
(anchorStyles & HorizontalAnchorStyles) == HorizontalAnchorStyles ? withinThis.Width : stretchThis.Width,
(anchorStyles & VerticalAnchorStyles) == VerticalAnchorStyles ? withinThis.Height : stretchThis.Height
);
if (stretchedSize.Width > withinThis.Width) {
stretchedSize.Width = withinThis.Width;
}
if (stretchedSize.Height > withinThis.Height) {
stretchedSize.Height = withinThis.Height;
}
return stretchedSize;
}
public static Rectangle InflateRect(Rectangle rect, Padding padding) {
rect.X -= padding.Left;
rect.Y -= padding.Top;
rect.Width += padding.Horizontal;
rect.Height += padding.Vertical;
return rect;
}
public static Rectangle DeflateRect(Rectangle rect, Padding padding) {
rect.X += padding.Left;
rect.Y += padding.Top;
rect.Width -= padding.Horizontal;
rect.Height -= padding.Vertical;
return rect;
}
public static Size AddAlignedRegion(Size textSize, Size imageSize, TextImageRelation relation) {
return AddAlignedRegionCore(textSize, imageSize, IsVerticalRelation(relation));
}
public static Size AddAlignedRegionCore(Size currentSize, Size contentSize, bool vertical) {
if(vertical) {
currentSize.Width = Math.Max(currentSize.Width, contentSize.Width);
currentSize.Height += contentSize.Height;
} else {
currentSize.Width += contentSize.Width;
currentSize.Height = Math.Max(currentSize.Height, contentSize.Height);
}
return currentSize;
}
public static Padding FlipPadding(Padding padding) {
// If Padding.All != -1, then TLRB are all the same and there is no work to be done.
if(padding.All != -1) {
return padding;
}
// Padding is a stuct (passed by value, no need to make a copy)
int temp;
temp = padding.Top;
padding.Top = padding.Left;
padding.Left = temp;
temp = padding.Bottom;
padding.Bottom = padding.Right;
padding.Right = temp;
return padding;
}
public static Point FlipPoint(Point point) {
// Point is a struct (passed by value, no need to make a copy)
int temp = point.X;
point.X = point.Y;
point.Y = temp;
return point;
}
public static Rectangle FlipRectangle(Rectangle rect) {
// Rectangle is a stuct (passed by value, no need to make a copy)
rect.Location = FlipPoint(rect.Location);
rect.Size = FlipSize(rect.Size);
return rect;
}
public static Rectangle FlipRectangleIf(bool condition, Rectangle rect) {
return condition ? FlipRectangle(rect) : rect;
}
public static Size FlipSize(Size size) {
// Size is a struct (passed by value, no need to make a copy)
int temp = size.Width;
size.Width = size.Height;
size.Height = temp;
return size;
}
public static Size FlipSizeIf(bool condition, Size size) {
return condition ? FlipSize(size) : size;
}
public static bool IsHorizontalAlignment(ContentAlignment align) {
return !IsVerticalAlignment(align);
}
// True if text & image should be lined up horizontally. False if vertical or overlay.
public static bool IsHorizontalRelation(TextImageRelation relation) {
return (relation & (TextImageRelation.TextBeforeImage | TextImageRelation.ImageBeforeText)) != 0;
}
public static bool IsVerticalAlignment(ContentAlignment align) {
Debug.Assert(align != ContentAlignment.MiddleCenter, "Result is ambiguous with an alignment of MiddleCenter.");
return (align & (ContentAlignment.TopCenter | ContentAlignment.BottomCenter)) != 0;
}
// True if text & image should be lined up vertically. False if horizontal or overlay.
public static bool IsVerticalRelation(TextImageRelation relation) {
return (relation & (TextImageRelation.TextAboveImage | TextImageRelation.ImageAboveText)) != 0;
}
public static bool IsZeroWidthOrHeight(Rectangle rectangle) {
return (rectangle.Width == 0 || rectangle.Height == 0);
}
public static bool IsZeroWidthOrHeight(Size size) {
return (size.Width == 0 || size.Height == 0);
}
public static bool AreWidthAndHeightLarger(Size size1, Size size2){
return ((size1.Width >= size2.Width) && (size1.Height >= size2.Height));
}
public static void SplitRegion(Rectangle bounds, Size specifiedContent, AnchorStyles region1Align, out Rectangle region1, out Rectangle region2) {
region1 = region2 = bounds;
switch(region1Align) {
case AnchorStyles.Left:
region1.Width = specifiedContent.Width;
region2.X += specifiedContent.Width;
region2.Width -= specifiedContent.Width;
break;
case AnchorStyles.Right:
region1.X += bounds.Width - specifiedContent.Width;
region1.Width = specifiedContent.Width;
region2.Width -= specifiedContent.Width;
break;
case AnchorStyles.Top:
region1.Height = specifiedContent.Height;
region2.Y += specifiedContent.Height;
region2.Height -= specifiedContent.Height;
break;
case AnchorStyles.Bottom:
region1.Y += bounds.Height - specifiedContent.Height;
region1.Height = specifiedContent.Height;
region2.Height -= specifiedContent.Height;
break;
default:
Debug.Fail("Unsupported value for region1Align.");
break;
}
Debug.Assert(Rectangle.Union(region1, region2) == bounds,
"Regions do not add up to bounds.");
}
// Expands adjacent regions to bounds. region1Align indicates which way the adjacency occurs.
public static void ExpandRegionsToFillBounds(Rectangle bounds, AnchorStyles region1Align, ref Rectangle region1, ref Rectangle region2) {
switch(region1Align) {
case AnchorStyles.Left:
Debug.Assert(region1.Right == region2.Left, "Adjacency error.");
region1 = SubstituteSpecifiedBounds(bounds, region1, AnchorStyles.Right);
region2 = SubstituteSpecifiedBounds(bounds, region2, AnchorStyles.Left);
break;
case AnchorStyles.Right:
Debug.Assert(region2.Right == region1.Left, "Adjacency error.");
region1 = SubstituteSpecifiedBounds(bounds, region1, AnchorStyles.Left);
region2 = SubstituteSpecifiedBounds(bounds, region2, AnchorStyles.Right);
break;
case AnchorStyles.Top:
Debug.Assert(region1.Bottom == region2.Top, "Adjacency error.");
region1 = SubstituteSpecifiedBounds(bounds, region1, AnchorStyles.Bottom);
region2 = SubstituteSpecifiedBounds(bounds, region2, AnchorStyles.Top);
break;
case AnchorStyles.Bottom:
Debug.Assert(region2.Bottom == region1.Top, "Adjacency error.");
region1 = SubstituteSpecifiedBounds(bounds, region1, AnchorStyles.Top);
region2 = SubstituteSpecifiedBounds(bounds, region2, AnchorStyles.Bottom);
break;
default:
Debug.Fail("Unsupported value for region1Align.");
break;
}
Debug.Assert(Rectangle.Union(region1, region2) == bounds, "region1 and region2 do not add up to bounds.");
}
public static Size SubAlignedRegion(Size currentSize, Size contentSize, TextImageRelation relation) {
return SubAlignedRegionCore(currentSize, contentSize, IsVerticalRelation(relation));
}
public static Size SubAlignedRegionCore(Size currentSize, Size contentSize, bool vertical) {
if(vertical) {
currentSize.Height -= contentSize.Height;
} else {
currentSize.Width -= contentSize.Width;
}
return currentSize;
}
private static Rectangle SubstituteSpecifiedBounds(Rectangle originalBounds, Rectangle substitutionBounds, AnchorStyles specified) {
int left = (specified & AnchorStyles.Left) != 0 ? substitutionBounds.Left : originalBounds.Left;
int top = (specified & AnchorStyles.Top) != 0 ? substitutionBounds.Top : originalBounds.Top;
int right = (specified & AnchorStyles.Right) != 0 ? substitutionBounds.Right : originalBounds.Right;
int bottom = (specified & AnchorStyles.Bottom) != 0 ? substitutionBounds.Bottom : originalBounds.Bottom;
return Rectangle.FromLTRB(left, top, right, bottom);
}
// given a rectangle, flip to the other side of (withinBounds)
//
// Never call this if you derive from ScrollableControl
public static Rectangle RTLTranslate(Rectangle bounds, Rectangle withinBounds) {
bounds.X = withinBounds.Width - bounds.Right;
return bounds;
}
/// MeasureTextCache
/// Cache mechanism added for VSWhidbey 500516
/// 3000 character strings take 9 seconds to load the form
public sealed class MeasureTextCache {
private Size unconstrainedPreferredSize = LayoutUtils.InvalidSize;
private const int MaxCacheSize = 6; // the number of preferred sizes to store
private int nextCacheEntry = -1; // the next place in the ring buffer to store a preferred size
private PreferredSizeCache[] sizeCacheList; // MRU of size MaxCacheSize
/// InvalidateCache
/// Clears out the cached values, should be called whenever Text, Font or a TextFormatFlag has changed
public void InvalidateCache() {
unconstrainedPreferredSize = LayoutUtils.InvalidSize;
sizeCacheList = null;
}
/// GetTextSize
/// Given constraints, format flags a font and text, determine the size of the string
/// employs an MRU of the last several constraints passed in via a ring-buffer of size MaxCacheSize.
/// Assumes Text and TextFormatFlags are the same, if either were to change, a call to
/// InvalidateCache should be made
public Size GetTextSize(string text, Font font, Size proposedConstraints, TextFormatFlags flags) {
if (!TextRequiresWordBreak(text, font, proposedConstraints, flags)) {
// Text fits within proposed width
// IF we're here, this means we've got text that can fit into the proposedConstraints
// without wrapping. We've determined this because our
// as a side effect of calling TextRequiresWordBreak,
// unconstrainedPreferredSize is set.
return unconstrainedPreferredSize;
}
else {
// Text does NOT fit within proposed width - requires WordBreak
// IF we're here, this means that the wrapping width is smaller
// than our max width. For example: we measure the text with infinite
// bounding box and we determine the width to fit all the characters
// to be 200 px wide. We would come here only for proposed widths less
// than 200 px.
// Create our ring buffer if we dont have one
if (sizeCacheList == null) {
sizeCacheList = new PreferredSizeCache[MaxCacheSize];
}
// check the existing constraints from previous calls
foreach (PreferredSizeCache sizeCache in sizeCacheList) {
if (sizeCache.ConstrainingSize == proposedConstraints) {
return sizeCache.PreferredSize;
}
else if ((sizeCache.ConstrainingSize.Width == proposedConstraints.Width)
&& (sizeCache.PreferredSize.Height <= proposedConstraints.Height)) {
// Caching a common case where the width matches perfectly, and the stored preferred height
// is smaller or equal to the constraining size.
// prefSize = GetPreferredSize(w,Int32.MaxValue);
// prefSize = GetPreferredSize(w,prefSize.Height);
return sizeCache.PreferredSize;
}
//
}
// if we've gotten here, it means we dont have a cache entry, therefore
// we should add a new one in the next available slot.
Size prefSize = TextRenderer.MeasureText(text, font, proposedConstraints, flags);
nextCacheEntry = (nextCacheEntry+1)%MaxCacheSize;
sizeCacheList[nextCacheEntry] = new PreferredSizeCache(proposedConstraints, prefSize);
return prefSize;
}
}
/// GetUnconstrainedSize
/// Gets the unconstrained (Int32.MaxValue, Int32.MaxValue) size for a piece of text
private Size GetUnconstrainedSize(string text, Font font, TextFormatFlags flags) {
if (unconstrainedPreferredSize == LayoutUtils.InvalidSize) {
// we also investigated setting the SingleLine flag, however this did not yield as much benefit as the word break
// and had possibility of causing internationalization issues.
flags = (flags & ~TextFormatFlags.WordBreak); // rip out the wordbreak flag
unconstrainedPreferredSize = TextRenderer.MeasureText(text, font, LayoutUtils.MaxSize, flags);
}
return unconstrainedPreferredSize;
}
/// TextRequiresWordBreak
/// If you give the text all the space in the world it wants, then there should be no reason
/// for it to break on a word. So we find out what the unconstrained size is (Int32.MaxValue, Int32.MaxValue)
/// for a string - eg. 35, 13. If the size passed in has a larger width than 35, then we know that
/// the WordBreak flag is not necessary.
public bool TextRequiresWordBreak(string text, Font font, Size size, TextFormatFlags flags) {
// if the unconstrained size of the string is larger than the proposed width
// we need the word break flag, otherwise we dont, its a perf hit to use it.
return GetUnconstrainedSize(text, font, flags).Width > size.Width;
}
private struct PreferredSizeCache {
public PreferredSizeCache(Size constrainingSize, Size preferredSize) {
this.ConstrainingSize = constrainingSize;
this.PreferredSize = preferredSize;
}
public Size ConstrainingSize;
public Size PreferredSize;
}
}
}
// Frequently when you need to do a PreformLayout, you also need to invalidate the
// PreferredSizeCache (you are laying out because you know that the action has changed
// the PreferredSize of the control and/or its container). LayoutTransaction wraps both
// of these operations into one, plus adds a check for null to make our code more
// concise.
//
// Usage1: (When we are not calling to other code which may cause a layout:)
//
// LayoutTransaction.DoLayout(ParentInternal, this, PropertyNames.Bounds);
//
// Usage2: (When we need to wrap code which may cause additional layouts:)
//
// using(new LayoutTransaction(ParentInternal, this, PropertyNames.Bounds)) {
// OnBoundsChanged();
// }
//
// The second usage spins off 12b for garbage collection, but I did some profiling and
// it didn't seem significant (we were spinning off more from LayoutEventArgs.)
internal sealed class LayoutTransaction : IDisposable {
Control _controlToLayout;
bool _resumeLayout;
#if DEBUG
int _layoutSuspendCount;
#endif
public LayoutTransaction(Control controlToLayout, IArrangedElement controlCausingLayout, string property) :
this(controlToLayout, controlCausingLayout, property, true) {
}
public LayoutTransaction(Control controlToLayout, IArrangedElement controlCausingLayout, string property, bool resumeLayout) {
CommonProperties.xClearPreferredSizeCache(controlCausingLayout);
_controlToLayout = controlToLayout;
_resumeLayout = resumeLayout;
if(_controlToLayout != null) {
#if DEBUG
_layoutSuspendCount = _controlToLayout.LayoutSuspendCount;
#endif
_controlToLayout.SuspendLayout();
CommonProperties.xClearPreferredSizeCache(_controlToLayout);
// Same effect as calling performLayout on Dispose but then we would have to keep
// controlCausingLayout and property around as state.
if (resumeLayout) {
_controlToLayout.PerformLayout(new LayoutEventArgs(controlCausingLayout, property));
}
}
}
public void Dispose() {
if(_controlToLayout != null) {
_controlToLayout.ResumeLayout(_resumeLayout);
#if DEBUG
Debug.Assert(_controlToLayout.LayoutSuspendCount == _layoutSuspendCount, "Suspend/Resume layout mismatch!");
#endif
}
}
// This overload should be used when a property has changed that affects preferred size,
// but you only want to layout if a certain condition exists (say you want to layout your
// parent because your preferred size has changed).
public static IDisposable CreateTransactionIf(bool condition, Control controlToLayout, IArrangedElement elementCausingLayout, string property) {
if (condition) {
return new LayoutTransaction(controlToLayout, elementCausingLayout, property);
}
else {
CommonProperties.xClearPreferredSizeCache(elementCausingLayout);
return new NullLayoutTransaction();
}
}
public static void DoLayout(IArrangedElement elementToLayout, IArrangedElement elementCausingLayout, string property) {
if (elementCausingLayout != null) {
CommonProperties.xClearPreferredSizeCache(elementCausingLayout);
if(elementToLayout != null) {
CommonProperties.xClearPreferredSizeCache(elementToLayout);
elementToLayout.PerformLayout(elementCausingLayout, property);
}
}
Debug.Assert(elementCausingLayout != null, "LayoutTransaction.DoLayout - elementCausingLayout is null, no layout performed - did you mix up your parameters?");
}
// This overload should be used when a property has changed that affects preferred size,
// but you only want to layout if a certain condition exists (say you want to layout your
// parent because your preferred size has changed).
public static void DoLayoutIf(bool condition, IArrangedElement elementToLayout, IArrangedElement elementCausingLayout, string property) {
if (!condition) {
if (elementCausingLayout != null) {
CommonProperties.xClearPreferredSizeCache(elementCausingLayout);
}
}
else {
LayoutTransaction.DoLayout(elementToLayout, elementCausingLayout, property);
}
}
}
internal struct NullLayoutTransaction : IDisposable {
public void Dispose() {
}
}
}
// File provided for Reference Use Only by Microsoft Corporation (c) 2007.
// Copyright (c) Microsoft Corporation. All rights reserved.
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