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Field appearance alignment refinements with some options.

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This commit is contained in:
Gunnsteinn Hall 2018-10-12 00:53:41 +00:00
parent bc6391200a
commit 817d0dc805
2 changed files with 261 additions and 48 deletions
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278
pdf/annotator/field_appearance.go
View File

@ -39,16 +39,23 @@ type AppearanceStyle struct {
BorderColor model.PdfColor
FillColor model.PdfColor
// Multiplier for lineheight for multi line text.
MultilineLineHeight float64
MultilineVAlignMiddle bool // Defaults to top.
// Visual guide checking alignment of field contents (debugging).
DrawAlignmentReticle bool
// Allow field MK appearance characteristics to override style settings.
AllowMK bool
}
var (
defaultAutoFontSizeFraction = 0.818
defaultCheckmarkGlyph = "a20"
defaultBorderSize = 0.0
defaultBorderColor = model.NewPdfColorDeviceGray(0)
defaultFillColor = model.NewPdfColorDeviceGray(1)
type quadding int
const (
quaddingLeft quadding = 0
quaddingCenter quadding = 1
quaddingRight quadding = 2
)
// SetStyle applies appearance `style` to `fa`.
@ -61,13 +68,17 @@ func (fa FieldAppearance) Style() AppearanceStyle {
if fa.style != nil {
return *fa.style
}
// Default values returned if style not set.
return AppearanceStyle{
AutoFontSizeFraction: defaultAutoFontSizeFraction,
CheckmarkGlyph: defaultCheckmarkGlyph,
BorderSize: defaultBorderSize,
BorderColor: defaultBorderColor,
FillColor: defaultFillColor,
AllowMK: true,
AutoFontSizeFraction: 0.65,
CheckmarkGlyph: "a20",
BorderSize: 0.0,
BorderColor: model.NewPdfColorDeviceGray(0),
FillColor: model.NewPdfColorDeviceGray(1),
MultilineLineHeight: 1.2,
MultilineVAlignMiddle: false,
DrawAlignmentReticle: false,
AllowMK: true,
}
}
@ -185,6 +196,14 @@ func genFieldTextAppearance(wa *model.PdfAnnotationWidget, ftxt *model.PdfFieldT
if style.BorderSize > 0 {
drawRect(cc, style, width, height)
}
if style.DrawAlignmentReticle {
// Alignment reticle.
style2 := style
style2.BorderSize = 0.2
drawAlignmentReticle(cc, style2, width, height)
}
cc.Add_BMC("Tx")
cc.Add_q()
// Graphic state changes.
@ -246,6 +265,10 @@ func genFieldTextAppearance(wa *model.PdfAnnotationWidget, ftxt *model.PdfFieldT
resources.SetFontByName(*fontname, fontobj)
}
encoder := font.Encoder()
fdescriptor, err := font.GetFontDescriptor()
if err != nil {
common.Log.Debug("Error: Unable to get font descriptor")
}
text := ""
if str, ok := core.GetString(ftxt.V); ok {
@ -259,9 +282,6 @@ func genFieldTextAppearance(wa *model.PdfAnnotationWidget, ftxt *model.PdfFieldT
lines := []string{text}
var tx float64
tx = 2.0 // Default left margin. // TODO(gunnsth): Add to style options.
// Handle multi line fields.
isMultiline := false
if ftxt.Flags().Has(model.FieldFlagMultiline) {
@ -323,64 +343,123 @@ func genFieldTextAppearance(wa *model.PdfAnnotationWidget, ftxt *model.PdfFieldT
}
}
var tx float64
tx = 2.0
// Check if text goes out of bounds, if goes out of bounds, then adjust font size until just within bounds.
if fontsize == 0 || autosize && maxLinewidth > 0 && tx+maxLinewidth*fontsize/1000.0 > width {
// TODO(gunnsth): Add to style options.
fontsize = 0.95 * 1000.0 * (width - tx) / maxLinewidth
}
var alignment quadding = quaddingLeft
// Account for horizontal alignment (quadding).
{
quadding := 0 // Default (left aligned).
if val, has := core.GetIntVal(ftxt.Q); has {
quadding = val
}
switch quadding {
case 0: // Left aligned.
case 1: // Centered.
remaining := width - maxLinewidth*fontsize/1000.0
if remaining > 0 {
tx = remaining / 2
switch val {
case 0: // Left aligned.
alignment = quaddingLeft
case 1: // Centered.
alignment = quaddingCenter
case 2: // Right justified.
alignment = quaddingRight
default:
common.Log.Debug("ERROR: Unsupported quadding: %d - using left alignment", val)
}
case 2: // Right justified.
remaining := width - maxLinewidth*fontsize/1000.0
tx = remaining
default:
common.Log.Debug("ERROR: Unsupported quadding: %d", quadding)
}
}
lineheight := 1.0 * fontsize
lh := style.MultilineLineHeight
lineheight := fontsize
if isMultiline && textlines > 1 {
lineheight = lh * fontsize
}
var fcapheight float64
if fdescriptor != nil {
fcapheight, err = fdescriptor.GetCapHeight()
if err != nil {
common.Log.Debug("ERROR: Unable to get font CapHeight: %v", err)
}
}
if int(fcapheight) <= 0 {
common.Log.Debug("WARN: CapHeight not available - setting to 1000")
fcapheight = 1000
}
capheight := fcapheight / 1000.0 * fontsize
// Vertical alignment.
ty := 2.0
ty := 0.0
{
textheight := float64(textlines) * lineheight
if autosize && ty+textheight > height {
fontsize = 0.95 * (height - ty) / float64(textlines)
lineheight = 1.0 * fontsize
lineheight = fontsize
if isMultiline && textlines > 1 {
lineheight = lh * fontsize
}
capheight = fcapheight / 1000.0 * fontsize
textheight = float64(textlines) * lineheight
}
if height > textheight {
if len(lines) > 1 {
a := (height - textheight) / 2.0
b := a + textheight - lineheight
ty = b
if isMultiline {
if style.MultilineVAlignMiddle {
a := (height - textheight) / 2.0
b := a + textheight - lineheight
ty = b
} else {
// Top.
ty = height - lineheight
ty -= fontsize * 0.5
}
} else {
ty = (height - textheight) / 2.0
ty += 1.50 // TODO(gunnsth): Make configurable/part of style parameter.
ty = (height - capheight) / 2.0
}
}
}
cc.Add_Tf(*fontname, fontsize)
cc.Add_Td(tx, ty)
tx0 := tx
x := tx
for i, line := range lines {
wLine := 0.0
for _, r := range line {
glyph, has := encoder.RuneToGlyph(r)
if !has {
common.Log.Debug("Encoder w/o rune '%c' (%X) - skip", r, r)
continue
}
metrics, has := font.GetGlyphCharMetrics(glyph)
if !has {
continue
}
wLine += metrics.Wx
}
linewidth := wLine / 1000.0 * fontsize
remaining := width - linewidth
var xnew float64
switch alignment {
case quaddingLeft:
xnew = tx0
case quaddingCenter:
xnew = remaining / 2
case quaddingRight:
xnew = remaining
}
tx = xnew - x
if tx > 0.0 {
cc.Add_Td(tx, 0)
}
x = xnew
cc.Add_Tj(*core.MakeString(line))
if i < len(lines)-1 {
cc.Add_Td(0, -lineheight)
cc.Add_Td(0, -lineheight*lh)
}
}
@ -450,6 +529,12 @@ func genFieldTextCombAppearance(wa *model.PdfAnnotationWidget, ftxt *model.PdfFi
if style.BorderSize > 0 {
drawRect(cc, style, width, height)
}
if style.DrawAlignmentReticle {
// Alignment reticle.
style2 := style
style2.BorderSize = 0.2
drawAlignmentReticle(cc, style2, width, height)
}
cc.Add_BMC("Tx")
cc.Add_q()
// Graphic state changes.
@ -459,9 +544,11 @@ func genFieldTextCombAppearance(wa *model.PdfAnnotationWidget, ftxt *model.PdfFi
var fontsize float64
var fontname *core.PdfObjectName
var font *model.PdfFont
autosize := true
fontsizeDef := height * style.AutoFontSizeFraction
for _, op := range *daOps {
// TODO: If TF specified and font size is 0, it means we should set on our own based on the Rect.
// If TF specified and font size is 0, it means we should set on our own based on the Rect.
if op.Operand == "Tf" && len(op.Params) == 2 {
if name, ok := core.GetName(op.Params[0]); ok {
fontname = name
@ -475,8 +562,12 @@ func genFieldTextCombAppearance(wa *model.PdfAnnotationWidget, ftxt *model.PdfFi
if fontsize == 0 {
// Use default if zero.
fontsize = fontsizeDef
} else {
// Disable autosize when font size (>0) explicitly specified.
autosize = false
}
op.Params[1] = core.MakeFloat(fontsize)
// Skip over (set fontsize in code below).
continue
}
cc.AddOperand(*op)
}
@ -506,14 +597,79 @@ func genFieldTextCombAppearance(wa *model.PdfAnnotationWidget, ftxt *model.PdfFi
resources.SetFontByName(*fontname, fontobj)
}
encoder := font.Encoder()
if encoder == nil {
common.Log.Debug("ERROR - Encoder is nil - can expect bad results")
}
text := ""
if str, ok := core.GetString(ftxt.V); ok {
text = str.Decoded()
}
// TODO(gunnsth): Add to style options.
ty := 0.26 * height
cc.Add_Tf(*fontname, fontsize)
// Get max glyph height.
maxGlyphWy := 0.0
for _, r := range text {
if encoder != nil {
glyph, has := encoder.RuneToGlyph(r)
if !has {
common.Log.Debug("ERROR: Rune not found %#v - skipping over", r)
continue
}
metrics, found := font.GetGlyphCharMetrics(glyph)
if !found {
common.Log.Debug("ERROR: Glyph not found in font: %v - skipping over", glyph)
continue
}
wy := metrics.Wy
if wy <= 0 {
wy = metrics.Wx
}
if wy > maxGlyphWy {
maxGlyphWy = wy
}
}
}
if int(maxGlyphWy) == 0 {
common.Log.Debug("ERROR: Unable to determine max glyph size - using 1000")
maxGlyphWy = 1000
}
fdescriptor, err := font.GetFontDescriptor()
if err != nil {
common.Log.Debug("Error: Unable to get font descriptor")
}
var fcapheight float64
if fdescriptor != nil {
fcapheight, err = fdescriptor.GetCapHeight()
if err != nil {
common.Log.Debug("ERROR: Unable to get font CapHeight: %v", err)
}
}
if int(fcapheight) <= 0 {
common.Log.Debug("WARN: CapHeight not available - setting to 1000")
fcapheight = 1000.0
}
capheight := fcapheight / 1000.0 * fontsize
// Vertical alignment.
ty := 0.0
lineheight := 1.0 * fontsize * (maxGlyphWy / 1000.0)
{
textheight := lineheight
// If autosize and going out of bounds, reduce to fit.
if autosize && ty+textheight > height {
fontsize = 0.95 * (height - ty)
lineheight = 1.0 * fontsize
textheight = lineheight
capheight = fcapheight / 1000.0 * fontsize
}
if height > capheight {
ty = (height - capheight) / 2.0
}
}
cc.Add_Td(0, ty)
if quadding, has := core.GetIntVal(ftxt.Q); has {
@ -613,6 +769,13 @@ func genFieldCheckboxAppearance(wa *model.PdfAnnotationWidget, fbtn *model.PdfFi
drawRect(cc, style, width, height)
}
if style.DrawAlignmentReticle {
// Alignment reticle.
style2 := style
style2.BorderSize = 0.2
drawAlignmentReticle(cc, style2, width, height)
}
fontsize := style.AutoFontSizeFraction * height
checkmetrics, ok := zapfdb.GetGlyphCharMetrics(style.CheckmarkGlyph)
@ -624,10 +787,10 @@ func genFieldCheckboxAppearance(wa *model.PdfAnnotationWidget, fbtn *model.PdfFi
return nil, errors.New("checkmark glyph - charcode mapping not found")
}
checkwidth := checkmetrics.Wx * fontsize / 1000.0
checkheight := checkwidth
if checkmetrics.Wy > 0 {
checkheight = checkmetrics.Wy * fontsize / 1000.0
}
// TODO: Get bbox of specific glyph that is chosen. Choice of specific value will cause slight
// deviations for other glyphs, but should be fairly close.
fcheckheight := 705.0 // From AFM for code 52.
checkheight := fcheckheight / 1000.0 * fontsize
tx := 2.0
ty := 1.0
@ -637,7 +800,6 @@ func genFieldCheckboxAppearance(wa *model.PdfAnnotationWidget, fbtn *model.PdfFi
if checkheight < height {
ty = (height - checkheight) / 2.0
}
ty += 1.0
cc.Add_q().
Add_g(0).
@ -753,6 +915,12 @@ func makeComboboxTextXObjForm(width, height float64, text string, style Appearan
if style.BorderSize > 0 {
drawRect(cc, style, width, height)
}
if style.DrawAlignmentReticle {
// Alignment reticle.
style2 := style
style2.BorderSize = 0.2
drawAlignmentReticle(cc, style2, width, height)
}
cc.Add_BMC("Tx")
cc.Add_q()
// Graphic state changes.
@ -915,6 +1083,20 @@ func drawRect(cc *contentstream.ContentCreator, style AppearanceStyle, width, he
Add_Q()
}
// drawAlignmentReticle draws the Rect box with a reticle on top for alignment guidance.
func drawAlignmentReticle(cc *contentstream.ContentCreator, style AppearanceStyle, width, height float64) {
cc.Add_q().
Add_re(0, 0, width, height).
Add_re(0, height/2, width, height/2).
Add_re(0, 0, width, height).
Add_re(width/2, 0, width/2, height).
Add_w(style.BorderSize).
SetStrokingColor(style.BorderColor).
SetNonStrokingColor(style.FillColor).
Add_B().
Add_Q()
}
// Apply appearance characteristics from an MK dictionary `mkDict` to appearance `style`.
// `font` is necessary when the "normal caption" (CA) field is specified (checkboxes).
func (style *AppearanceStyle) applyAppearanceCharacteristics(mkDict *core.PdfObjectDictionary, bsDict *core.PdfObjectDictionary, font *model.PdfFont) error {

31
pdf/model/font.go
View File

@ -27,6 +27,22 @@ type PdfFont struct {
context fonts.Font // The underlying font: Type0, Type1, Truetype, etc..
}
// GetFontDescriptor returns the font descriptor for `font`.
func (font PdfFont) GetFontDescriptor() (*PdfFontDescriptor, error) {
switch t := font.context.(type) {
case *pdfFontSimple:
return t.fontDescriptor, nil
case *pdfFontType0:
return t.fontDescriptor, nil
case *pdfCIDFontType0:
return t.fontDescriptor, nil
case *pdfCIDFontType2:
return t.fontDescriptor, nil
}
common.Log.Debug("ERROR: Cannot get font descriptor for font type %t (%s)", font, font)
return nil, errors.New("fontdescriptor not found")
}
// String returns a string that describes `font`.
func (font PdfFont) String() string {
enc := ""
@ -650,6 +666,21 @@ type PdfFontDescriptor struct {
container *core.PdfIndirectObject
}
// GetDescent returns the Descent of the font `descriptor`.
func (descriptor *PdfFontDescriptor) GetDescent() (float64, error) {
return core.GetNumberAsFloat(descriptor.Descent)
}
// GetAscent returns the Ascent of the font `descriptor`.
func (descriptor *PdfFontDescriptor) GetAscent() (float64, error) {
return core.GetNumberAsFloat(descriptor.Ascent)
}
// GetCapHeight returns the CapHeight of the font `descriptor`.
func (descriptor *PdfFontDescriptor) GetCapHeight() (float64, error) {
return core.GetNumberAsFloat(descriptor.CapHeight)
}
// String returns a string describing the font descriptor.
func (descriptor *PdfFontDescriptor) String() string {
parts := []string{}