C++ BFont::StringWidth方法代码示例

float
PieView::_DrawDirectory(BRect b, FileInfo* info, float parentSpan,
	float beginAngle, int colorIdx, int level)
{
	if (b.Width() < 2.0 * (kPieCenterSize + level * kPieRingSize
		+ kPieOuterMargin + kPieInnerMargin)) {
		return 0.0;
	}

	if (info != NULL && info->color >= 0 && level == 0)
		colorIdx = info->color % kBasePieColorCount;
	else if (info != NULL)
		info->color = colorIdx;

	VolumeSnapshot* snapshot = fScanner->Snapshot();

	float cx = floorf(b.left + b.Width() / 2.0 + 0.5);
	float cy = floorf(b.top + b.Height() / 2.0 + 0.5);

	float mySpan;

	if (level == 0) {
		// Make room for mouse over info.
		fMouseOverInfo.clear();
		fMouseOverInfo[0] = SegmentList();

		// Draw the center circle.
		const char* displayName;
		if (info == NULL) {
			// NULL represents the entire volume.  Show used and free space in
			// the center circle, with the used segment representing the
			// volume's root directory.
			off_t volCapacity = snapshot->capacity;
			mySpan = 360.0 * (volCapacity - snapshot->freeBytes) / volCapacity;

			SetHighColor(kEmptySpcColor);
			FillEllipse(BPoint(cx, cy), kPieCenterSize, kPieCenterSize);

			SetHighColor(kBasePieColor[0]);
			FillArc(BPoint(cx, cy), kPieCenterSize, kPieCenterSize, 0.0,
				mySpan);

			// Show total volume capacity.
			char label[B_PATH_NAME_LENGTH];
			size_to_string(volCapacity, label, sizeof(label));
			SetHighColor(kPieBGColor);
			SetDrawingMode(B_OP_OVER);
			DrawString(label, BPoint(cx - StringWidth(label) / 2.0,
				cy + fFontHeight + kSmallVMargin));
			SetDrawingMode(B_OP_COPY);

			displayName = snapshot->name.c_str();

			// Record in-use space and free space for use during MouseMoved().
			info = snapshot->rootDir;
			info->color = colorIdx;
			fMouseOverInfo[0].push_back(Segment(0.0, mySpan, info));
			if (mySpan < 360.0 - kMinSegmentSpan) {
				fMouseOverInfo[0].push_back(Segment(mySpan, 360.0,
					snapshot->freeSpace));
			}
		} else {
			// Show a normal directory.
			SetHighColor(kBasePieColor[colorIdx]);
			FillEllipse(BRect(cx - kPieCenterSize, cy - kPieCenterSize,
				cx + kPieCenterSize + 0.5, cy + kPieCenterSize + 0.5));
			displayName = info->ref.name;
			mySpan = 360.0;

			// Record the segment for use during MouseMoved().
			fMouseOverInfo[0].push_back(Segment(0.0, mySpan, info));
		}

		SetPenSize(1.0);
		SetHighColor(kOutlineColor);
		StrokeEllipse(BPoint(cx, cy), kPieCenterSize + 0.5,
			kPieCenterSize + 0.5);

		// Show the name of the volume or directory.
		BString label(displayName);
		BFont font;
		GetFont(&font);
		font.TruncateString(&label, B_TRUNCATE_END,
			2.0 * (kPieCenterSize - kSmallHMargin));
		float labelWidth = font.StringWidth(label.String());

		SetHighColor(kPieBGColor);
		SetDrawingMode(B_OP_OVER);
		DrawString(label.String(), BPoint(cx - labelWidth / 2.0, cy));
		SetDrawingMode(B_OP_COPY);
		beginAngle = 0.0;
	} else {
		// Draw an exterior segment.
		float parentSize;
		if (info->parent == NULL)
			parentSize = (float)snapshot->capacity;
		else
			parentSize = (float)info->parent->size;

		mySpan = parentSpan * (float)info->size / parentSize;
//.........这里部分代码省略.........

void
FontSelectionView::UpdateFontsMenu()
{
	int32 numFamilies = count_font_families();

	fFontsMenu->RemoveItems(0, fFontsMenu->CountItems(), true);
	BFont font;
	fFontsMenu->GetFont(&font);

	font_family currentFamily;
	font_style currentStyle;
	fCurrentFont.GetFamilyAndStyle(&currentFamily, &currentStyle);

	for (int32 i = 0; i < numFamilies; i++) {
		font_family family;
		uint32 flags;
		if (get_font_family(i, &family, &flags) != B_OK)
			continue;

		// if we're setting the fixed font, we only want to show fixed fonts
		if (!strcmp(Name(), "fixed") && (flags & B_IS_FIXED) == 0)
			continue;

		float width = font.StringWidth(family);
		if (width > fMaxFontNameWidth)
			fMaxFontNameWidth = width;

		BMenu* stylesMenu = new BMenu(family);
		stylesMenu->SetRadioMode(true);
		stylesMenu->SetFont(&font);

		BMessage* message = new BMessage(kMsgSetFamily);
		message->AddString("family", family);
		message->AddString("name", Name());

		BMenuItem* familyItem = new BMenuItem(stylesMenu, message);
		fFontsMenu->AddItem(familyItem);

		int32 numStyles = count_font_styles(family);

		for (int32 j = 0; j < numStyles; j++) {
			font_style style;
			if (get_font_style(family, j, &style, &flags) != B_OK)
				continue;

			message = new BMessage(kMsgSetStyle);
			message->AddString("family", (char*)family);
			message->AddString("style", (char*)style);
			message->AddString("name", Name());

			BMenuItem *item = new BMenuItem(style, message);

			if (!strcmp(style, currentStyle)
				&& !strcmp(family, currentFamily)) {
				item->SetMarked(true);
				familyItem->SetMarked(true);
			}
			stylesMenu->AddItem(item);
		}
	}
}

void
ExpressionTextView::SetValue(BString value)
{
	// save the value
	fCurrentValue = value;

	// calculate the width of the string
	BFont font;
	uint32 mode = B_FONT_ALL;
	GetFontAndColor(&font, &mode);
	float stringWidth = font.StringWidth(value);

	// make the string shorter if it does not fit in the view
	float viewWidth = Frame().Width();
	if (value.CountChars() > 3 && stringWidth > viewWidth) {
		// get the position of the first digit
		int32 firstDigit = 0;
		if (value[0] == '-')
			firstDigit++;

		// calculate the value of the exponent
		int32 exponent = 0;
		int32 offset = value.FindFirst('.');
		if (offset == B_ERROR) {
			exponent = value.CountChars() - 1 - firstDigit;
			value.Insert('.', 1, firstDigit + 1);
		} else {
			if (offset == firstDigit + 1) {
				// if the value is 0.01 or larger then scientific notation
				// won't shorten the string
				if (value[firstDigit] != '0' || value[firstDigit + 2] != '0' 
					|| value[firstDigit + 3] != '0') {
					exponent = 0;
				} else {
					// remove the period
					value.Remove(offset, 1);

					// check for negative exponent value
					exponent = 0;
					while (value[firstDigit] == '0') {
						value.Remove(firstDigit, 1);
						exponent--;
					}

					// add the period
					value.Insert('.', 1, firstDigit + 1);
				}
			} else {
				// if the period + 1 digit fits in the view scientific notation
				// won't shorten the string
				BString temp = value;
				temp.Truncate(offset + 2);
				stringWidth = font.StringWidth(temp);
				if (stringWidth < viewWidth)
					exponent = 0;
				else {
					// move the period
					value.Remove(offset, 1);
					value.Insert('.', 1, firstDigit + 1);
					
					exponent = offset - (firstDigit + 1);
				}
			}
		}

		// add the exponent
		offset = value.CountChars() - 1;
		if (exponent != 0)
			value << "E" << exponent;

		// reduce the number of digits until the string fits or can not be
		// made any shorter
		stringWidth = font.StringWidth(value);
		char lastRemovedDigit = '0';
		while (offset > firstDigit && stringWidth > viewWidth) {
			if (value[offset] != '.')	
				lastRemovedDigit = value[offset];
			value.Remove(offset--, 1);
			stringWidth = font.StringWidth(value);
		}

		// there is no need to keep the period if no digits follow
		if (value[offset] == '.') {
			value.Remove(offset, 1);
			offset--;
		}

		// take care of proper rounding of the result
		int digit = (int)lastRemovedDigit - '0'; // ascii to int
		if (digit >= 5) {
			for (; offset >= firstDigit; offset--) {
				if (value[offset] == '.')
					continue;
				digit = (int)(value[offset]) - '0' + 1; // ascii to int + 1
				if (digit != 10)
					break;
				value.Remove(offset, 1);
			}
			if (digit == 10) {
				// carry over, shift the result
//.........这里部分代码省略.........

void
BRadioButton::Draw(BRect updateRect)
{
	if (Window() == NULL) return;

	BFont font;
	GetFont(&font);
	font_height fontHeight;
	font.GetHeight(&fontHeight);
	float sHeight = fontHeight.ascent + fontHeight.descent;

	BRect rect = Frame().OffsetToSelf(B_ORIGIN);
	rect.InsetBy(5, (rect.Height() - sHeight) / 2);
	if (rect.IsValid() == false) return;

	if ((IsFocus() || IsFocusChanging()) && IsEnabled() && Label() != NULL) {
		BPoint penLocation;
		penLocation.Set(rect.left + rect.Height() + 5, rect.Center().y + sHeight / 2 + 1);

		SetHighColor((IsFocus() && Window()->IsActivate()) ? ui_color(B_NAVIGATION_BASE_COLOR) : ViewColor());
		StrokeLine(penLocation, penLocation + BPoint(font.StringWidth(Label()), 0));
	}

	if (IsFocusChanging()) return;

	rgb_color shineColor = ui_color(B_SHINE_COLOR);
	rgb_color shadowColor = ui_color(B_SHADOW_COLOR);

	if (!IsEnabled()) {
		shineColor.disable(ViewColor());
		shadowColor.disable(ViewColor());
	}

	rect.right = rect.left + rect.Height();
	SetHighColor(shineColor.mix_copy(0, 0, 0, 5));
	FillEllipse(rect);
	SetHighColor(shineColor);
	StrokeArc(rect, 225, 180);
	SetHighColor(shadowColor);
	StrokeArc(rect, 45, 180);

	if (Value() == B_CONTROL_ON) {
		SetHighColor(shadowColor.mix_copy(255, 255, 255, 50));
		BRect r = rect.InsetByCopy(3, 3);
		FillEllipse(r);
	}

	if (Label() != NULL) {
		BPoint penLocation;
		penLocation.x = rect.right + 5;
		penLocation.y = rect.Center().y - sHeight / 2.f;
		penLocation.y += fontHeight.ascent + 1;

		SetHighColor(IsEnabled() ? ui_color(B_PANEL_TEXT_COLOR) : ui_color(B_SHINE_COLOR).disable(ViewColor()));
		SetLowColor(ViewColor());

		DrawString(Label(), penLocation);
		if (!IsEnabled()) {
			SetHighColor(ui_color(B_SHADOW_COLOR).disable(ViewColor()));
			DrawString(Label(), penLocation - BPoint(1, 1));
		}
	}
}

//! Redraw the button depending on whether it's up or down
void
CPUButton::Draw(BRect rect)
{
	bool value = (bool)Value();
	SetHighColor(value ? fOnColor : fOffColor);

	if (!fReplicant) {
		SetLowColor(Parent()->LowColor());
		FillRect(Bounds(), B_SOLID_LOW);
	}

	BRect bounds = Bounds();
	if (fReplicant && !fReplicantInDeskbar) {
		bounds.bottom -= 4;
		bounds.right -= 4;
	} else if (!fReplicant) {
		bounds.bottom -= 7;
		bounds.right -= 7;
	}
	BRect color_rect(bounds);
	color_rect.InsetBy(2, 2);
	if (value) {
		color_rect.bottom -= 1;
		color_rect.right -= 1;
	}
	FillRect(bounds);

	if (value)
		SetHighColor(80, 80, 80);
	else
		SetHighColor(255, 255, 255);

	BPoint start(0, 0);
	BPoint end(bounds.right, 0);
	StrokeLine(start, end);
	end.Set(0, bounds.bottom);
	StrokeLine(start, end);

	if (value)
		SetHighColor(32, 32, 32);
	else
		SetHighColor(216, 216, 216);

	start.Set(1, 1);
	end.Set(bounds.right - 1, 1);
	StrokeLine(start, end);
	end.Set(1, bounds.bottom - 1);
	StrokeLine(start, end);

	if (value)
		SetHighColor(216, 216, 216);
	else
		SetHighColor(80, 80, 80);

	start.Set(bounds.left + 1, bounds.bottom - 1);
	end.Set(bounds.right - 1, bounds.bottom - 1);
	StrokeLine(start, end);
	start.Set(bounds.right - 1, bounds.top + 1);
	StrokeLine(start, end);

	if (value)
		SetHighColor(255, 255, 255);
	else
		SetHighColor(32, 32, 32);

	start.Set(bounds.left, bounds.bottom);
	end.Set(bounds.right, bounds.bottom);
	StrokeLine(start, end);
	start.Set(bounds.right, bounds.top);
	StrokeLine(start, end);

	if (value) {
		SetHighColor(0, 0, 0);
		start.Set(bounds.left + 2, bounds.bottom - 2);
		end.Set(bounds.right - 2, bounds.bottom - 2);
		StrokeLine(start, end);
		start.Set(bounds.right - 2, bounds.top + 2);
		StrokeLine(start, end);
	}

	// Try to keep the text centered
	BFont font;
	GetFont(&font);
	int label_width = (int)font.StringWidth(Label());
	int rect_width = bounds.IntegerWidth() - 1;
	int rect_height = bounds.IntegerHeight();
	font_height fh;
	font.GetHeight(&fh);
	int label_height = (int)fh.ascent;
	int x_pos = (int)(((double)(rect_width - label_width) / 2.0) + 0.5);
	int y_pos = (rect_height - label_height) / 2 + label_height;

	MovePenTo(x_pos, y_pos);
	SetHighColor(0, 0, 0);
	SetDrawingMode(B_OP_OVER);
	DrawString(Label());
}