app, io: [wasm, android] add support for numeric/email keyboard mode

Previously, the on-screen keyboard always displays the text keyboard,
(QWERTY or equivalent).

For optimal user experience, it's possible to specify the keyboard type
using `InputHint`. The on-screen keyboard will provide shortcuts or
restrict what the user can input.

Due to some limitations (gio#116), only numeric and text keyboards are
supported on Android.

Signed-off-by: Inkeliz <inkeliz@inkeliz.com>

app/internal/wm/GioView.java

@@ -36,6 +36,7 @@ import android.view.inputmethod.BaseInputConnection;
 import android.view.inputmethod.InputConnection;
 import android.view.inputmethod.InputMethodManager;
 import android.view.inputmethod.EditorInfo;
+import android.text.InputType;
 
 import java.io.UnsupportedEncodingException;
 
@@ -47,6 +48,7 @@ public final class GioView extends SurfaceView implements Choreographer.FrameCal
 	private final InputMethodManager imm;
 	private final float scrollXScale;
 	private final float scrollYScale;
+	private int keyboardHint;
 
 	private long nhandle;
 
@@ -247,10 +249,20 @@ public final class GioView extends SurfaceView implements Choreographer.FrameCal
 		}
 	}
 
-	@Override public InputConnection onCreateInputConnection(EditorInfo outAttrs) {
+	@Override public InputConnection onCreateInputConnection(EditorInfo editor) {
+		editor.inputType = this.keyboardHint;
+		editor.imeOptions = EditorInfo.IME_FLAG_NO_FULLSCREEN | EditorInfo.IME_FLAG_NO_EXTRACT_UI;
 		return new InputConnection(this);
 	}
 
+	void setInputHint(int hint) {
+	    if (hint == this.keyboardHint) {
+	        return;
+	    }
+	    this.keyboardHint = hint;
+	    imm.restartInput(this);
+	}
+
 	void showTextInput() {
 		GioView.this.requestFocus();
 		imm.showSoftInput(GioView.this, 0);

app/internal/wm/os_android.go

@@ -152,6 +152,7 @@ var gioView struct {
 	getFontScale       C.jmethodID
 	showTextInput      C.jmethodID
 	hideTextInput      C.jmethodID
+	setInputHint       C.jmethodID
 	postFrameCallback  C.jmethodID
 	setCursor          C.jmethodID
 	setOrientation     C.jmethodID
@@ -281,6 +282,7 @@ func Java_org_gioui_GioView_onCreateView(env *C.JNIEnv, class C.jclass, view C.j
 		m.getFontScale = getMethodID(env, class, "getFontScale", "()F")
 		m.showTextInput = getMethodID(env, class, "showTextInput", "()V")
 		m.hideTextInput = getMethodID(env, class, "hideTextInput", "()V")
+		m.setInputHint = getMethodID(env, class, "setInputHint", "(I)V")
 		m.postFrameCallback = getMethodID(env, class, "postFrameCallback", "()V")
 		m.setCursor = getMethodID(env, class, "setCursor", "(I)V")
 		m.setOrientation = getMethodID(env, class, "setOrientation", "(II)V")
@@ -609,6 +611,28 @@ func (w *window) ShowTextInput(show bool) {
 	})
 }
 
+func (w *window) SetInputHint(mode key.InputHint) {
+	// Constants defined at https://developer.android.com/reference/android/text/InputType.
+	const (
+		TYPE_NULL                = 0
+		TYPE_CLASS_NUMBER        = 2
+		TYPE_NUMBER_FLAG_DECIMAL = 8192
+		TYPE_NUMBER_FLAG_SIGNED  = 4096
+	)
+
+	runInJVM(javaVM(), func(env *C.JNIEnv) {
+		var m jvalue
+		switch mode {
+		case key.HintNumeric:
+			m = TYPE_CLASS_NUMBER | TYPE_NUMBER_FLAG_DECIMAL | TYPE_NUMBER_FLAG_SIGNED
+		default:
+			// TYPE_NULL, since TYPE_CLASS_TEXT isn't currently supported (gio#116), so TYPE_NULL is used instead.
+			m = TYPE_NULL
+		}
+		callVoidMethod(env, w.view, gioView.setInputHint, m)
+	})
+}
+
 func javaString(env *C.JNIEnv, str string) C.jstring {
 	if str == "" {
 		return 0

app/internal/wm/os_ios.go

@@ -297,6 +297,8 @@ func (w *window) ShowTextInput(show bool) {
 	}
 }
 
+func (w *window) SetInputHint(_ key.InputHint) {}
+
 // Close the window. Not implemented for iOS.
 func (w *window) Close() {}
 

app/internal/wm/os_js.go

@@ -313,6 +313,27 @@ func (w *window) focus() {
 	w.requestFocus = true
 }
 
+func (w *window) keyboard(hint key.InputHint) {
+	var m string
+	switch hint {
+	case key.HintAny:
+		m = "text"
+	case key.HintText:
+		m = "text"
+	case key.HintNumeric:
+		m = "decimal"
+	case key.HintEmail:
+		m = "email"
+	case key.HintURL:
+		m = "url"
+	case key.HintTelephone:
+		m = "tel"
+	default:
+		m = "text"
+	}
+	w.tarea.Set("inputMode", m)
+}
+
 func (w *window) keyEvent(e js.Value, ks key.State) {
 	k := e.Get("key").String()
 	if n, ok := translateKey(k); ok {
@@ -524,6 +545,10 @@ func (w *window) ShowTextInput(show bool) {
 	}()
 }
 
+func (w *window) SetInputHint(mode key.InputHint) {
+	w.keyboard(mode)
+}
+
 // Close the window. Not implemented for js.
 func (w *window) Close() {}
 

app/internal/wm/os_macos.go

@@ -187,6 +187,8 @@ func (w *window) SetCursor(name pointer.CursorName) {
 
 func (w *window) ShowTextInput(show bool) {}
 
+func (w *window) SetInputHint(_ key.InputHint) {}
+
 func (w *window) SetAnimating(anim bool) {
 	if anim {
 		w.displayLink.Start()

app/internal/wm/os_wayland.go

@@ -1462,6 +1462,8 @@ func (w *window) surface() (*C.struct_wl_surface, int, int) {
 
 func (w *window) ShowTextInput(show bool) {}
 
+func (w *window) SetInputHint(_ key.InputHint) {}
+
 // Close the window. Not implemented for Wayland.
 func (w *window) Close() {}
 

app/internal/wm/os_windows.go

@@ -665,6 +665,8 @@ func loadCursor(name pointer.CursorName) (syscall.Handle, error) {
 
 func (w *window) ShowTextInput(show bool) {}
 
+func (w *window) SetInputHint(_ key.InputHint) {}
+
 func (w *window) HDC() syscall.Handle {
 	return w.hdc
 }

app/internal/wm/os_x11.go

@@ -223,6 +223,8 @@ func (w *x11Window) SetWindowMode(mode WindowMode) {
 
 func (w *x11Window) ShowTextInput(show bool) {}
 
+func (w *x11Window) SetInputHint(_ key.InputHint) {}
+
 // Close the window.
 func (w *x11Window) Close() {
 	var xev C.XEvent

app/internal/wm/window.go

@@ -6,6 +6,7 @@ package wm
 
 import (
 	"errors"
+	"gioui.org/io/key"
 	"image/color"
 
 	"gioui.org/gpu"
@@ -84,8 +85,12 @@ type Driver interface {
 	// SetAnimating sets the animation flag. When the window is animating,
 	// FrameEvents are delivered as fast as the display can handle them.
 	SetAnimating(anim bool)
+
 	// ShowTextInput updates the virtual keyboard state.
 	ShowTextInput(show bool)
+
+	SetInputHint(mode key.InputHint)
+
 	NewContext() (Context, error)
 
 	// ReadClipboard requests the clipboard content.

app/window.go

@@ -184,6 +184,9 @@ func (w *Window) processFrame(frameStart time.Time, size image.Point, frame *op.
 	case router.TextInputClose:
 		go w.driverRun(func(d wm.Driver) { d.ShowTextInput(false) })
 	}
+	if hint, ok := w.queue.q.TextInputHint(); ok {
+		go w.driverRun(func(d wm.Driver) { d.SetInputHint(hint) })
+	}
 	if txt, ok := w.queue.q.WriteClipboard(); ok {
 		go w.WriteClipboard(txt)
 	}

internal/opconst/ops.go

@@ -50,8 +50,8 @@ const (
 	TypePassLen            = 1 + 1
 	TypeClipboardReadLen   = 1
 	TypeClipboardWriteLen  = 1
-	TypeKeyInputLen        = 1
-	TypeKeyFocusLen        = 1
+	TypeKeyInputLen        = 1 + 1
+	TypeKeyFocusLen        = 1 + 1
 	TypeKeySoftKeyboardLen = 1 + 1
 	TypeSaveLen            = 1 + 4
 	TypeLoadLen            = 1 + 1 + 4

io/key/key.go

@@ -22,7 +22,8 @@ import (
 // Key events are in general only delivered to the
 // focused key handler.
 type InputOp struct {
-	Tag event.Tag
+	Tag  event.Tag
+	Hint InputHint
 }
 
 // SoftKeyboardOp shows or hide the on-screen keyboard, if available.
@@ -64,6 +65,25 @@ type EditEvent struct {
 	Text string
 }
 
+// InputHint changes the on-screen-keyboard type. That hints the
+// type of data that might be entered by the user.
+type InputHint uint8
+
+const (
+	// HintAny hints that any input is expected.
+	HintAny InputHint = iota
+	// HintText hints that text input is expected. It may activate auto-correction and suggestions.
+	HintText
+	// HintNumeric hints that numeric input is expected. It may activate shortcuts for 0-9, "." and ",".
+	HintNumeric
+	// HintEmail hints that email input is expected. It may activate shortcuts for common email characters, such as "@" and ".com".
+	HintEmail
+	// HintURL hints that URL input is expected. It may activate shortcuts for common URL fragments such as "/" and ".com".
+	HintURL
+	// HintTelephone hints that telephone number input is expected. It may activate shortcuts for 0-9, "#" and "*".
+	HintTelephone
+)
+
 // State is the state of a key during an event.
 type State uint8
 
@@ -127,6 +147,7 @@ func (h InputOp) Add(o *op.Ops) {
 	}
 	data := o.Write1(opconst.TypeKeyInputLen, h.Tag)
 	data[0] = byte(opconst.TypeKeyInput)
+	data[1] = byte(h.Hint)
 }
 
 func (h SoftKeyboardOp) Add(o *op.Ops) {

io/router/key.go

@@ -17,6 +17,7 @@ type keyQueue struct {
 	handlers map[event.Tag]*keyHandler
 	reader   ops.Reader
 	state    TextInputState
+	hint     key.InputHint
 }
 
 type keyHandler struct {
@@ -24,6 +25,7 @@ type keyHandler struct {
 	// in the current frame.
 	visible bool
 	new     bool
+	hint    key.InputHint
 }
 
 const (
@@ -38,6 +40,20 @@ func (q *keyQueue) InputState() TextInputState {
 	return q.state
 }
 
+// InputHint returns the input mode from the most recent key.InputOp.
+func (q *keyQueue) InputHint() (key.InputHint, bool) {
+	if q.focus == nil {
+		return q.hint, false
+	}
+	focused, ok := q.handlers[q.focus]
+	if !ok {
+		return q.hint, false
+	}
+	old := q.hint
+	q.hint = focused.hint
+	return q.hint, old != q.hint
+}
+
 func (q *keyQueue) Frame(root *op.Ops, events *handlerEvents) {
 	if q.handlers == nil {
 		q.handlers = make(map[event.Tag]*keyHandler)
@@ -108,6 +124,7 @@ func (q *keyQueue) resolveFocus(events *handlerEvents) (focus event.Tag, changed
 				q.handlers[op.Tag] = h
 			}
 			h.visible = true
+			h.hint = op.Hint
 		}
 	}
 	return
@@ -118,7 +135,8 @@ func decodeKeyInputOp(d []byte, refs []interface{}) key.InputOp {
 		panic("invalid op")
 	}
 	return key.InputOp{
-		Tag: refs[0].(event.Tag),
+		Tag:  refs[0].(event.Tag),
+		Hint: key.InputHint(d[1]),
 	}
 }
 

io/router/router.go

@@ -102,6 +102,11 @@ func (q *Router) TextInputState() TextInputState {
 	return q.kqueue.InputState()
 }
 
+// TextInputHint returns the input mode from the most recent key.InputOp.
+func (q *Router) TextInputHint() (key.InputHint, bool) {
+	return q.kqueue.InputHint()
+}
+
 // WriteClipboard returns the most recent text to be copied
 // to the clipboard, if any.
 func (q *Router) WriteClipboard() (string, bool) {