v2rayN/v2rayN/v2rayN.Desktop/Views/MsgView.axaml.cs

using System.Reactive.Disposables;
using Avalonia.Controls;
using Avalonia.Interactivity;
using Avalonia.ReactiveUI;
using Avalonia.Threading;
using ReactiveUI;
using v2rayN.Desktop.Common;
using System.Text;

namespace v2rayN.Desktop.Views;

public partial class MsgView : ReactiveUserControl<MsgViewModel>
{
    private readonly ScrollViewer _scrollViewer;
    private const int _maxLines = 320;   // 实际保留的行数
    private const int _trimLines = 350;  // 超过此阈值时裁剪
    private int _lastShownLength = 0;

    public MsgView()
    {
        InitializeComponent();
        _scrollViewer = this.FindControl<ScrollViewer>("msgScrollViewer");

        ViewModel = new MsgViewModel(UpdateViewHandler);

        this.WhenActivated(disposables =>
        {
            this.Bind(ViewModel, vm => vm.MsgFilter, v => v.cmbMsgFilter.Text).DisposeWith(disposables);
            this.Bind(ViewModel, vm => vm.AutoRefresh, v => v.togAutoRefresh.IsChecked).DisposeWith(disposables);
        });
    }

    private async Task<bool> UpdateViewHandler(EViewAction action, object? obj)
    {
        switch (action)
        {
            case EViewAction.DispatcherShowMsg:
                if (obj is null) return false;

                Dispatcher.UIThread.Post(() =>
                    ShowMsg(obj),
                   DispatcherPriority.ApplicationIdle);
                break;
        }
        return await Task.FromResult(true);
    }

    private void ShowMsg(object msg)
    {
        var newText = msg?.ToString() ?? string.Empty;
        txtMsg.Text += newText;

        var lines = txtMsg.Text.Split(Environment.NewLine);
        if (lines.Length > _trimLines)
        {
            var sb = new StringBuilder();
            int start = lines.Length - _maxLines;
            for (int i = start; i < lines.Length; i++)
            {
                sb.Append(lines[i]);
                if (i < lines.Length - 1)
                    sb.Append(Environment.NewLine);
            }
            txtMsg.Text = sb.ToString();
        }

        _lastShownLength = txtMsg.Text.Length;

        if (togScrollToEnd.IsChecked ?? true)
            Avalonia.Threading.Dispatcher.UIThread.Post(
                () => _scrollViewer?.ScrollToEnd(),
                Avalonia.Threading.DispatcherPriority.Render);
    }

    public void ClearMsg()
    {
        ViewModel?.ClearMsg();
        txtMsg.Text = "";
        _lastShownLength = 0;
    }

    private void menuMsgViewSelectAll_Click(object? sender, RoutedEventArgs e)
    {
        txtMsg.Focus();
        txtMsg.SelectAll();
    }

    private async void menuMsgViewCopy_Click(object? sender, RoutedEventArgs e)
    {
        var data = txtMsg.SelectedText.TrimEx();
        await AvaUtils.SetClipboardData(this, data);
    }

    private async void menuMsgViewCopyAll_Click(object? sender, RoutedEventArgs e)
    {
        var data = txtMsg.Text.TrimEx();
        await AvaUtils.SetClipboardData(this, data);
    }

    private void menuMsgViewClear_Click(object? sender, RoutedEventArgs e)
    {
        ClearMsg();
    }
}