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Issue #932: [win32] implementation for StyledText.setFixedLineMetrics
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Signed-off-by: Alexandr Miloslavskiy <alexandr.miloslavskiy@syntevo.com>
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@SyntevoAlex
SyntevoAlex committed Jan 31, 2024
1 parent cd799ed commit 213d31a
Showing 1 changed file with 110 additions and 9 deletions.
119 changes: 110 additions & 9 deletions bundles/org.eclipse.swt/Eclipse SWT/win32/org/eclipse/swt/graphics/TextLayout.java
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Original file line number Diff line number Diff line change
Expand Up @@ -64,6 +64,8 @@ public final class TextLayout extends Resource {
IMLangFontLink2 mLangFontLink2;
int verticalIndentInPoints;

private MetricsAdapter metricsAdapter = new MetricsAdapter();

static final char LTR_MARK = '\u200E', RTL_MARK = '\u200F';
static final int SCRIPT_VISATTR_SIZEOF = 2;
static final int GOFFSET_SIZEOF = 8;
Expand Down Expand Up @@ -185,6 +187,100 @@ public String toString () {
}
}

private static class MetricsAdapter {
private TEXTMETRIC wantMetricsInPixels;

// Optimization: produce less GC garbage in frequent calls
TEXTMETRIC realMetricsInPixels = new TEXTMETRIC();

public boolean isFixedMetrics() {
return (wantMetricsInPixels != null);
}

public void setFixedLineMetrics(FontMetrics metrics) {
if (metrics == null) {
wantMetricsInPixels = null;
return;
}

TEXTMETRIC result = new TEXTMETRIC();
result.tmAscent = metrics.handle.tmAscent;
result.tmDescent = metrics.handle.tmDescent;
result.tmHeight = metrics.handle.tmHeight;
result.tmInternalLeading = metrics.handle.tmInternalLeading;
result.tmAveCharWidth = 0;

wantMetricsInPixels = result;
}

public int calcYAdjust(TEXTMETRIC realMetricsInPixels) {
// Adjust text position so that baseline is preserved:
// * Taller characters may go out of line bounds.
// * Shorter characters will fit and also stay on baseline.
//
// Note that without fixed line metrics mode, SWT doesn't
// align baseline. When different scripts are mixed, this
// causes baseline to "jump" up and down. I believe that
// this is an oversight.
return (wantMetricsInPixels.tmAscent - realMetricsInPixels.tmAscent);
}

public int calcYAdjust(long hdc) {
OS.GetTextMetrics(hdc, realMetricsInPixels);
return calcYAdjust(realMetricsInPixels);
}

public boolean GetTextMetrics(long hdc, TEXTMETRIC lptm) {
// Even in fixed mode, still call original to get `tmAveCharWidth` etc.
boolean ret = OS.GetTextMetrics(hdc, lptm);
if (!ret) return false;

if (isFixedMetrics()) {
// Force desired line metrics
lptm.tmAscent = wantMetricsInPixels.tmAscent;
lptm.tmDescent = wantMetricsInPixels.tmDescent;
lptm.tmHeight = wantMetricsInPixels.tmHeight;
lptm.tmInternalLeading = wantMetricsInPixels.tmInternalLeading;
}

return ret;
}

public int GetOutlineTextMetrics(long hdc, int cbData, OUTLINETEXTMETRIC lpOTM) {
// Even in fixed mode, still call original to get `tmAveCharWidth` etc.
int ret = OS.GetOutlineTextMetrics(hdc, cbData, lpOTM);
if (0 == ret) return 0;

if (isFixedMetrics()) {
TEXTMETRIC lptm = lpOTM.otmTextMetrics;

final int yAdjust = calcYAdjust(lptm);

// Force desired line metrics
lptm.tmAscent = wantMetricsInPixels.tmAscent;
lptm.tmDescent = wantMetricsInPixels.tmDescent;
lptm.tmHeight = wantMetricsInPixels.tmHeight;
lptm.tmInternalLeading = wantMetricsInPixels.tmInternalLeading;

// Also adjust underline/strikeout positions in the same
// way as text position will be adjusted when painting it
lpOTM.otmsUnderscorePosition += yAdjust;
lpOTM.otmsStrikeoutPosition += yAdjust;
}

return ret;
}

public int ScriptTextOut(long hdc, long psc, int x, int y, int fuOptions, RECT lprc, SCRIPT_ANALYSIS psa, long pwcReserved, int iReserved, long pwGlyphs, int cGlyphs, long piAdvance, long piJustify, long pGoffset) {
if (isFixedMetrics()) {
final int yAdjust = calcYAdjust(hdc);
y += yAdjust;
}

return OS.ScriptTextOut(hdc, psc, x, y, fuOptions, lprc, psa, pwcReserved, iReserved, pwGlyphs, cGlyphs, piAdvance, piJustify, pGoffset);
}
}

/**
* Constructs a new instance of this class on the given device.
* <p>
Expand Down Expand Up @@ -440,7 +536,7 @@ void computeRuns (GC gc) {
if (lineRunCount == 1 && (i == allRuns.length - 1 || !run.softBreak)) {
TEXTMETRIC lptm = new TEXTMETRIC();
OS.SelectObject(srcHdc, getItemFont(run));
OS.GetTextMetrics(srcHdc, lptm);
metricsAdapter.GetTextMetrics(srcHdc, lptm);
run.ascentInPoints = DPIUtil.autoScaleDown(getDevice(), lptm.tmAscent);
run.descentInPoints = DPIUtil.autoScaleDown(getDevice(), lptm.tmDescent);
ascentInPoints = Math.max(ascentInPoints, run.ascentInPoints);
Expand Down Expand Up @@ -1067,11 +1163,11 @@ RECT drawRunText(long hdc, StyleItem run, RECT rect, int baselineInPixels, int c
}
}
OS.SetTextColor(hdc, color);
OS.ScriptTextOut(hdc, run.psc, x, y, 0, null, run.analysis , 0, 0, run.glyphs, run.glyphCount, run.advances, run.justify, run.goffsets);
metricsAdapter.ScriptTextOut(hdc, run.psc, x, y, 0, null, run.analysis , 0, 0, run.glyphs, run.glyphCount, run.advances, run.justify, run.goffsets);
if (partialSelection) {
getPartialSelection(run, selectionStart, selectionEnd, rect);
OS.SetTextColor(hdc, selectionColor);
OS.ScriptTextOut(hdc, run.psc, x, y, OS.ETO_CLIPPED, rect, run.analysis , 0, 0, run.glyphs, run.glyphCount, run.advances, run.justify, run.goffsets);
metricsAdapter.ScriptTextOut(hdc, run.psc, x, y, OS.ETO_CLIPPED, rect, run.analysis , 0, 0, run.glyphs, run.glyphCount, run.advances, run.justify, run.goffsets);
}
return fullSelection || partialSelection ? rect : null;
}
Expand All @@ -1081,8 +1177,14 @@ RECT drawRunTextGDIP(long graphics, StyleItem run, RECT rect, long gdipFont, int
boolean hasSelection = selectionStart <= selectionEnd && selectionStart != -1 && selectionEnd != -1;
boolean fullSelection = hasSelection && selectionStart <= run.start && selectionEnd >= end;
boolean partialSelection = hasSelection && !fullSelection && !(selectionStart > end || run.start > selectionEnd);

// Note from a passerby: it seems that 'Graphics::DrawDriverString'
// puts baseline at requested position. This is different from GDI
// rendering (such as ScriptTextOut()) which put top of the character
// at requested position.
int drawY = rect.top + baselineInPixels;
if (run.style != null && run.style.rise != 0) drawY -= DPIUtil.autoScaleUp(getDevice(), run.style.rise);

int drawX = rect.left;
long brush = color;
if (fullSelection) {
Expand Down Expand Up @@ -1998,7 +2100,7 @@ public FontMetrics getLineMetrics (int lineIndex) {
long srcHdc = OS.CreateCompatibleDC(hDC);
TEXTMETRIC lptm = new TEXTMETRIC();
OS.SelectObject(srcHdc, font != null ? font.handle : device.systemFont.handle);
OS.GetTextMetrics(srcHdc, lptm);
metricsAdapter.GetTextMetrics(srcHdc, lptm);
OS.DeleteDC(srcHdc);
device.internal_dispose_GC(hDC, null);

Expand Down Expand Up @@ -3108,8 +3210,7 @@ public void setDescent (int descent) {
* @since 3.125
*/
public void setFixedLineMetrics (FontMetrics metrics) {
if (metrics == null) return;
SWT.error(SWT.ERROR_NOT_IMPLEMENTED);
metricsAdapter.setFixedLineMetrics(metrics);
}

/**
Expand Down Expand Up @@ -3798,7 +3899,7 @@ long metaFileEnumProc (long hDC, long table, long record, long nObj, long lpData
OUTLINETEXTMETRIC lotm = null;
if (style.underline || style.strikeout) {
lotm = new OUTLINETEXTMETRIC();
if (OS.GetOutlineTextMetrics(hdc, OUTLINETEXTMETRIC.sizeof, lotm) == 0) {
if (metricsAdapter.GetOutlineTextMetrics(hdc, OUTLINETEXTMETRIC.sizeof, lotm) == 0) {
lotm = null;
}
}
Expand All @@ -3819,7 +3920,7 @@ long metaFileEnumProc (long hDC, long table, long record, long nObj, long lpData
lptm = lotm.otmTextMetrics;
} else {
lptm = new TEXTMETRIC();
OS.GetTextMetrics(hdc, lptm);
metricsAdapter.GetTextMetrics(hdc, lptm);
}
run.ascentInPoints = DPIUtil.autoScaleDown(getDevice(), lptm.tmAscent);
run.descentInPoints = DPIUtil.autoScaleDown(getDevice(), lptm.tmDescent);
Expand All @@ -3840,7 +3941,7 @@ long metaFileEnumProc (long hDC, long table, long record, long nObj, long lpData
run.descentInPoints -= style.rise;
} else {
TEXTMETRIC lptm = new TEXTMETRIC();
OS.GetTextMetrics(hdc, lptm);
metricsAdapter.GetTextMetrics(hdc, lptm);
run.ascentInPoints = DPIUtil.autoScaleDown(getDevice(), lptm.tmAscent);
run.descentInPoints = DPIUtil.autoScaleDown(getDevice(), lptm.tmDescent);
run.leadingInPoints = DPIUtil.autoScaleDown(getDevice(), lptm.tmInternalLeading);
Expand Down

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