debugui: refactoring: remove internal/caller

Author: hajimehoshi

control.go

@@ -11,8 +11,6 @@ import (
 
 	"github.com/hajimehoshi/ebiten/v2"
 	"github.com/hajimehoshi/ebiten/v2/inpututil"
-
-	"github.com/ebitengine/debugui/internal/caller"
 )
 
 const idSeparator = "\x00"
@@ -94,7 +92,7 @@ func (c *Context) updateControl(id controlID, bounds image.Rectangle, opt option
 }
 
 func (c *Context) Control(idStr string, f func(bounds image.Rectangle) bool) bool {
-	pc := caller.Caller()
+	pc := caller()
 	var res bool
 	c.wrapError(func() error {
 		id := c.idFromCaller(pc, idStr)

export_test.go

@@ -3,14 +3,12 @@
 
 package debugui
 
-import "github.com/ebitengine/debugui/internal/caller"
-
 type ControlID = controlID
 
 const EmptyControlID = emptyControlID
 
 func (c *Context) ButtonID(label string) ControlID {
-	pc := caller.Caller()
+	pc := caller()
 	var id controlID
 	c.wrapError(func() error {
 		var err error

helpers.go

@@ -7,6 +7,7 @@ import (
 	"errors"
 	"fmt"
 	"image"
+	"runtime"
 	"slices"
 	"sort"
 	"unsafe"
@@ -19,6 +20,15 @@ func clamp[T int | float64](x, a, b T) T {
 	return min(b, max(a, x))
 }
 
+// caller returns a program counter of the caller.
+func caller() uintptr {
+	pc, _, _, ok := runtime.Caller(2)
+	if !ok {
+		return 0
+	}
+	return pc
+}
+
 func (c *Context) idFromGlobalUniquePointer(pointer unsafe.Pointer) controlID {
 	return controlID(fmt.Sprintf("!pointer:%p", pointer))
 }

internal/caller/caller.go

@@ -3,10 +3,8 @@
 
 package debugui
 
-import "github.com/ebitengine/debugui/internal/caller"
-
 func (c *Context) Panel(name string, f func(layout ContainerLayout)) {
-	pc := caller.Caller()
+	pc := caller()
 	c.wrapError(func() error {
 		if err := c.panel(name, 0, pc, f); err != nil {
 			return err

panel.go

@@ -3,10 +3,8 @@
 
 package debugui
 
-import "github.com/ebitengine/debugui/internal/caller"
-
 func (c *Context) Button(label string) bool {
-	pc := caller.Caller()
+	pc := caller()
 	var res bool
 	c.wrapError(func() error {
 		var err error
@@ -33,7 +31,7 @@ func (c *Context) Slider(value *float64, lo, hi float64, step float64, digits in
 }
 
 func (c *Context) Header(label string, expanded bool, f func()) {
-	pc := caller.Caller()
+	pc := caller()
 	c.wrapError(func() error {
 		var opt option
 		if expanded {
@@ -50,7 +48,7 @@ func (c *Context) Header(label string, expanded bool, f func()) {
 }
 
 func (c *Context) TreeNode(label string, f func()) {
-	pc := caller.Caller()
+	pc := caller()
 	c.wrapError(func() error {
 		if err := c.treeNode(label, 0, pc, f); err != nil {
 			return err

widget.go

@@ -8,12 +8,10 @@ import (
 
 	"github.com/hajimehoshi/ebiten/v2"
 	"github.com/hajimehoshi/ebiten/v2/inpututil"
-
-	"github.com/ebitengine/debugui/internal/caller"
 )
 
 func (c *Context) Window(title string, rect image.Rectangle, f func(layout ContainerLayout)) {
-	pc := caller.Caller()
+	pc := caller()
 	c.wrapError(func() error {
 		if err := c.window(title, rect, 0, pc, f); err != nil {
 			return err
@@ -178,7 +176,7 @@ func (c *Context) ClosePopup(name string) {
 }
 
 func (c *Context) Popup(name string, f func(layout ContainerLayout)) {
-	pc := caller.Caller()
+	pc := caller()
 	c.wrapError(func() error {
 		opt := optionPopup | optionAutoSize | optionNoResize | optionNoScroll | optionNoTitle | optionClosed
 		if err := c.window(name, image.Rectangle{}, opt, pc, f); err != nil {