Add get screen resolution code

errors.go

@@ -11,5 +11,6 @@ var (
 	ErrNotInstalled        = errors.New("adb is not installed or not in PATH")
 	ErrCoordinatesNotFound = errors.New("coordinates for an input event are missing")
 	ErrConnUSB             = errors.New("cannot call connect to device using USB")
+	ErrResolutionParseFail = errors.New("failed to parse screen size from input text")
 	ErrUnspecified         = errors.New("an unknown error has occurred, please open an issue on GitHub")
 )

examples/taps/main.go

@@ -0,0 +1,36 @@
+package main
+
+import (
+	"context"
+	"fmt"
+
+	"github.com/taigrr/adb"
+)
+
+var command string
+
+func init() {
+	// TODO  allow for any input to be used as the command
+	command = "ls"
+}
+
+func main() {
+	ctx := context.TODO()
+	devs, err := adb.Devices(ctx)
+	if err != nil {
+		fmt.Printf("Error enumerating devices: %v\n", err)
+		return
+	}
+	for _, dev := range devs {
+		if !dev.IsAuthorized {
+			fmt.Printf("Dev `%s` is not authorized, authorize it to continue.\n", dev.SerialNo)
+			continue
+		}
+		w, h, err := dev.GetScreenResolution(ctx)
+		if err != nil {
+			// handle error here
+			fmt.Printf("Error: %v\n", err)
+		}
+		fmt.Printf("%s screen resolution: %dx%d\n", dev.SerialNo, w, h)
+	}
+}

shell.go

@@ -2,6 +2,8 @@ package adb
 
 import (
 	"context"
+	"regexp"
+	"strconv"
 	"time"
 
 	"github.com/google/shlex"
@@ -26,8 +28,26 @@ func (d Device) Shell(ctx context.Context, command string) (stdout string, stder
 
 // adb shell wm size
 // Physical size: 1440x3120
-func (d Device) GetScreenResolution(ctx context.Context) (width int, lenght int, err error) {
+func (d Device) GetScreenResolution(ctx context.Context) (width int, height int, err error) {
-	return 0, 0, nil
+	cmd := []string{"-s", string(d.SerialNo), "shell", "wm", "size"}
+	stdout, _, _, err := execute(ctx, cmd)
+	if err != nil {
+		return -1, -1, err
+	}
+	return parseScreenResolution(stdout)
+}
+
+// Parses input, example:
+// Physical size: 1440x3040
+func parseScreenResolution(in string) (int, int, error) {
+	r := regexp.MustCompile(`Physical size: ([0-9]+)x([0-9]+)`)
+	resStr := r.FindStringSubmatch(in)
+	if len(resStr) != 3 {
+		return -1, -1, ErrResolutionParseFail
+	}
+	w, _ := strconv.Atoi(resStr[1])
+	h, _ := strconv.Atoi(resStr[2])
+	return w, h, nil
 }
 
 func (d Device) Tap(ctx context.Context, X, Y int) error {

shell_test.go

@@ -0,0 +1,36 @@
+package adb
+
+import "testing"
+
+func Test_parseScreenResolution(t *testing.T) {
+	type args struct {
+		in string
+	}
+	tests := []struct {
+		name       string
+		args       args
+		wantWidth  int
+		wantLength int
+		wantErr    bool
+	}{
+		{name: "Pixel 4XL", args: args{in: "Physical size: 1440x3040"}, wantWidth: 1440, wantLength: 3040, wantErr: false},
+		{name: "Pixel XL", args: args{in: "Physical size: 1440x2560"}, wantWidth: 1440, wantLength: 2560, wantErr: false},
+		{name: "garbage", args: args{in: "asdfhjkla"}, wantWidth: -1, wantLength: -1, wantErr: true},
+		// TODO: Add test cases.
+	}
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			w, l, err := parseScreenResolution(tt.args.in)
+			if (err != nil) != tt.wantErr {
+				t.Errorf("parseScreenResolution() error = %v, wantErr %v", err, tt.wantErr)
+				return
+			}
+			if w != tt.wantWidth {
+				t.Errorf("parseScreenResolution() got = %v, want %v", w, tt.wantWidth)
+			}
+			if l != tt.wantLength {
+				t.Errorf("parseScreenResolution() got1 = %v, want %v", l, tt.wantLength)
+			}
+		})
+	}
+}