vise/render/size.go

115 lines
3.1 KiB
Go
Raw Normal View History

package render
import (
"bytes"
"fmt"
"log"
"strings"
)
2023-04-12 19:04:36 +02:00
// Sizer splits dynamic contents into individual segments for browseable pages.
type Sizer struct {
2023-04-12 19:04:36 +02:00
outputSize uint32 // maximum output for a single page.
menuSize uint16 // actual menu size for the dynamic page being sized
memberSizes map[string]uint16 // individual byte sizes of all content to be rendered by template.
totalMemberSize uint32 // total byte size of all content to be rendered by template (sum of memberSizes)
crsrs []uint32 // byte offsets in the sink content for browseable pages indices.
sink string // sink symbol.
}
2023-04-12 19:04:36 +02:00
// NewSizer creates a new Sizer object with the given output size constraint.
func NewSizer(outputSize uint32) *Sizer {
return &Sizer{
outputSize: outputSize,
memberSizes: make(map[string]uint16),
}
}
2023-04-12 19:04:36 +02:00
// WithMenuSize sets the size of the menu being used in the rendering context.
func(szr *Sizer) WithMenuSize(menuSize uint16) *Sizer {
szr.menuSize = menuSize
return szr
}
2023-04-12 19:04:36 +02:00
// Set adds a content symbol in the state it will be used by the renderer.
func(szr *Sizer) Set(key string, size uint16) error {
szr.memberSizes[key] = size
if size == 0 {
szr.sink = key
}
szr.totalMemberSize += uint32(size)
return nil
}
2023-04-12 19:04:36 +02:00
// Check audits whether the rendered string is within the output size constraint of the sizer.
func(szr *Sizer) Check(s string) (uint32, bool) {
l := uint32(len(s))
2023-04-07 10:30:23 +02:00
if szr.outputSize > 0 {
if l > szr.outputSize {
log.Printf("sizer check fails with length %v: %s", l, szr)
log.Printf("sizer contents:\n%s", s)
2023-04-07 10:30:23 +02:00
return 0, false
}
l = szr.outputSize - l
}
return l, true
}
2023-04-12 19:04:36 +02:00
// String implements the String interface.
func(szr *Sizer) String() string {
var diff uint32
if szr.outputSize > 0 {
diff = szr.outputSize - szr.totalMemberSize - uint32(szr.menuSize)
}
return fmt.Sprintf("output: %v, member: %v, menu: %v, diff: %v", szr.outputSize, szr.totalMemberSize, szr.menuSize, diff)
}
2023-04-07 10:30:23 +02:00
2023-04-12 19:04:36 +02:00
// Size gives the byte size of content for a single symbol.
//
// Fails if the symbol has not been registered using Set
2023-04-07 10:30:23 +02:00
func(szr *Sizer) Size(s string) (uint16, error) {
r, ok := szr.memberSizes[s]
if !ok {
return 0, fmt.Errorf("unknown member: %s", s)
}
return r, nil
}
2023-04-12 19:04:36 +02:00
// Menusize returns the currently defined menu size.
func(szr *Sizer) MenuSize() uint16 {
return szr.menuSize
}
2023-04-12 19:04:36 +02:00
// AddCursor adds a pagination cursor for the paged sink content.
func(szr *Sizer) AddCursor(c uint32) {
log.Printf("added cursor: %v", c)
szr.crsrs = append(szr.crsrs, c)
}
2023-04-12 19:04:36 +02:00
// GetAt the paged symbols for the current page index.
//
// Fails if index requested is out of range.
func(szr *Sizer) GetAt(values map[string]string, idx uint16) (map[string]string, error) {
if szr.sink == "" {
return values, nil
}
outValues := make(map[string]string)
for k, v := range values {
if szr.sink == k {
if idx >= uint16(len(szr.crsrs)) {
return nil, fmt.Errorf("no more values in index")
}
c := szr.crsrs[idx]
v = v[c:]
nl := strings.Index(v, "\n")
if nl > 0 {
v = v[:nl]
}
b := bytes.ReplaceAll([]byte(v), []byte{0x00}, []byte{0x0a})
v = string(b)
}
outValues[k] = v
}
return outValues, nil
}