XCEngine/new_editor/app/Platform/Win32/EditorWindowTitleBarInteraction.cpp

#include "Platform/Win32/EditorWindow.h"
#include "Platform/Win32/EditorWindowConstants.h"

#include <algorithm>

#include <windowsx.h>

namespace XCEngine::UI::Editor::App {

using namespace EditorWindowSupport;

bool EditorWindow::UpdateBorderlessWindowChromeHover(LPARAM lParam) {
    if (m_chrome.runtime.GetHoveredBorderlessResizeEdge() !=
            Host::BorderlessWindowResizeEdge::None ||
        m_chrome.runtime.IsBorderlessResizeActive()) {
        const bool changed =
            m_chrome.chromeState.hoveredTarget !=
            Host::BorderlessWindowChromeHitTarget::None;
        m_chrome.chromeState.hoveredTarget =
            Host::BorderlessWindowChromeHitTarget::None;
        return changed;
    }

    const Host::BorderlessWindowChromeHitTarget hitTarget =
        HitTestBorderlessWindowChrome(lParam);
    const Host::BorderlessWindowChromeHitTarget buttonTarget =
        hitTarget == Host::BorderlessWindowChromeHitTarget::MinimizeButton ||
            hitTarget == Host::BorderlessWindowChromeHitTarget::MaximizeRestoreButton ||
            hitTarget == Host::BorderlessWindowChromeHitTarget::CloseButton
        ? hitTarget
        : Host::BorderlessWindowChromeHitTarget::None;
    if (m_chrome.chromeState.hoveredTarget == buttonTarget) {
        return false;
    }

    m_chrome.chromeState.hoveredTarget = buttonTarget;
    return true;
}

bool EditorWindow::HandleBorderlessWindowChromeButtonDown(LPARAM lParam) {
    if (m_chrome.runtime.GetHoveredBorderlessResizeEdge() !=
            Host::BorderlessWindowResizeEdge::None ||
        m_chrome.runtime.IsBorderlessResizeActive()) {
        return false;
    }

    const Host::BorderlessWindowChromeHitTarget hitTarget =
        HitTestBorderlessWindowChrome(lParam);
    switch (hitTarget) {
    case Host::BorderlessWindowChromeHitTarget::MinimizeButton:
    case Host::BorderlessWindowChromeHitTarget::MaximizeRestoreButton:
    case Host::BorderlessWindowChromeHitTarget::CloseButton:
        m_chrome.chromeState.pressedTarget = hitTarget;
        if (m_window.hwnd != nullptr) {
            SetCapture(m_window.hwnd);
        }
        InvalidateHostWindow();
        return true;
    case Host::BorderlessWindowChromeHitTarget::DragRegion:
        if (m_window.hwnd != nullptr) {
            if (IsBorderlessWindowMaximized()) {
                POINT screenPoint = {};
                if (GetCursorPos(&screenPoint)) {
                    m_chrome.runtime.BeginBorderlessWindowDragRestore(screenPoint);
                    SetCapture(m_window.hwnd);
                    return true;
                }
            }

            ReleaseCapture();
            SendMessageW(m_window.hwnd, WM_NCLBUTTONDOWN, HTCAPTION, 0);
        }
        return true;
    case Host::BorderlessWindowChromeHitTarget::None:
    default:
        return false;
    }
}

bool EditorWindow::HandleBorderlessWindowChromeButtonUp(
    EditorContext& editorContext,
    bool globalTabDragActive,
    LPARAM lParam) {
    if (m_chrome.runtime.IsBorderlessWindowDragRestoreArmed()) {
        ClearBorderlessWindowChromeDragRestoreState();
        return true;
    }

    const Host::BorderlessWindowChromeHitTarget pressedTarget =
        m_chrome.chromeState.pressedTarget;
    if (pressedTarget != Host::BorderlessWindowChromeHitTarget::MinimizeButton &&
        pressedTarget != Host::BorderlessWindowChromeHitTarget::MaximizeRestoreButton &&
        pressedTarget != Host::BorderlessWindowChromeHitTarget::CloseButton) {
        return false;
    }

    const Host::BorderlessWindowChromeHitTarget releasedTarget =
        HitTestBorderlessWindowChrome(lParam);
    m_chrome.chromeState.pressedTarget =
        Host::BorderlessWindowChromeHitTarget::None;
    if (GetCapture() == m_window.hwnd) {
        ReleaseCapture();
    }
    InvalidateHostWindow();

    if (pressedTarget == releasedTarget) {
        ExecuteBorderlessWindowChromeAction(
            editorContext,
            globalTabDragActive,
            pressedTarget);
    }
    return true;
}

bool EditorWindow::HandleBorderlessWindowChromeDoubleClick(
    EditorContext& editorContext,
    bool globalTabDragActive,
    LPARAM lParam) {
    if (m_chrome.runtime.IsBorderlessWindowDragRestoreArmed()) {
        ClearBorderlessWindowChromeDragRestoreState();
    }

    if (HitTestBorderlessWindowChrome(lParam) !=
        Host::BorderlessWindowChromeHitTarget::DragRegion) {
        return false;
    }

    ExecuteBorderlessWindowChromeAction(
        editorContext,
        globalTabDragActive,
        Host::BorderlessWindowChromeHitTarget::MaximizeRestoreButton);
    return true;
}

bool EditorWindow::HandleBorderlessWindowChromeDragRestorePointerMove(
    EditorContext& editorContext,
    bool globalTabDragActive) {
    if (!m_chrome.runtime.IsBorderlessWindowDragRestoreArmed() || m_window.hwnd == nullptr) {
        return false;
    }

    POINT currentScreenPoint = {};
    if (!GetCursorPos(&currentScreenPoint)) {
        return true;
    }

    const POINT initialScreenPoint =
        m_chrome.runtime.GetBorderlessWindowDragRestoreInitialScreenPoint();
    const int dragThresholdX = (std::max)(GetSystemMetrics(SM_CXDRAG), 1);
    const int dragThresholdY = (std::max)(GetSystemMetrics(SM_CYDRAG), 1);
    const LONG deltaX = currentScreenPoint.x - initialScreenPoint.x;
    const LONG deltaY = currentScreenPoint.y - initialScreenPoint.y;
    if (std::abs(deltaX) < dragThresholdX &&
        std::abs(deltaY) < dragThresholdY) {
        return true;
    }

    RECT restoreRect = {};
    RECT currentRect = {};
    RECT workAreaRect = {};
    if (!m_chrome.runtime.TryGetBorderlessWindowRestoreRect(restoreRect) ||
        !QueryCurrentWindowRect(currentRect) ||
        !QueryBorderlessWindowWorkAreaRect(workAreaRect)) {
        ClearBorderlessWindowChromeDragRestoreState();
        return true;
    }

    const int restoreWidth = restoreRect.right - restoreRect.left;
    const int restoreHeight = restoreRect.bottom - restoreRect.top;
    const int currentWidth = currentRect.right - currentRect.left;
    if (restoreWidth <= 0 || restoreHeight <= 0 || currentWidth <= 0) {
        ClearBorderlessWindowChromeDragRestoreState();
        return true;
    }

    const float pointerRatio =
        static_cast<float>(currentScreenPoint.x - currentRect.left) /
        static_cast<float>(currentWidth);
    const float clampedPointerRatio = (std::clamp)(pointerRatio, 0.0f, 1.0f);
    const int newLeft =
        (std::clamp)(
            currentScreenPoint.x -
                static_cast<int>(clampedPointerRatio * static_cast<float>(restoreWidth)),
            workAreaRect.left,
            workAreaRect.right - restoreWidth);
    const int titleBarHeightPixels =
        static_cast<int>(kBorderlessTitleBarHeightDips * GetDpiScale());
    const int newTop =
        (std::clamp)(
            currentScreenPoint.y - (std::max)(titleBarHeightPixels / 2, 1),
            workAreaRect.top,
            workAreaRect.bottom - restoreHeight);
    const RECT targetRect = {
        newLeft,
        newTop,
        newLeft + restoreWidth,
        newTop + restoreHeight
    };

    m_chrome.runtime.SetBorderlessWindowMaximized(false);
    ApplyPredictedWindowRectTransition(
        editorContext,
        globalTabDragActive,
        targetRect);
    ClearBorderlessWindowChromeDragRestoreState();
    ReleaseCapture();
    SendMessageW(m_window.hwnd, WM_NCLBUTTONDOWN, HTCAPTION, 0);
    return true;
}

void EditorWindow::ClearBorderlessWindowChromeDragRestoreState() {
    if (!m_chrome.runtime.IsBorderlessWindowDragRestoreArmed()) {
        return;
    }

    m_chrome.runtime.EndBorderlessWindowDragRestore();
    if (GetCapture() == m_window.hwnd) {
        ReleaseCapture();
    }
}

void EditorWindow::ClearBorderlessWindowChromeState() {
    if (m_chrome.chromeState.hoveredTarget ==
            Host::BorderlessWindowChromeHitTarget::None &&
        m_chrome.chromeState.pressedTarget ==
            Host::BorderlessWindowChromeHitTarget::None) {
        return;
    }

    m_chrome.chromeState = {};
    InvalidateHostWindow();
}

void EditorWindow::ExecuteBorderlessWindowChromeAction(
    EditorContext& editorContext,
    bool globalTabDragActive,
    Host::BorderlessWindowChromeHitTarget target) {
    if (m_window.hwnd == nullptr) {
        return;
    }

    switch (target) {
    case Host::BorderlessWindowChromeHitTarget::MinimizeButton:
        ShowWindow(m_window.hwnd, SW_MINIMIZE);
        break;
    case Host::BorderlessWindowChromeHitTarget::MaximizeRestoreButton:
        ToggleBorderlessWindowMaximizeRestore(editorContext, globalTabDragActive);
        break;
    case Host::BorderlessWindowChromeHitTarget::CloseButton:
        PostMessageW(m_window.hwnd, WM_CLOSE, 0, 0);
        break;
    case Host::BorderlessWindowChromeHitTarget::DragRegion:
    case Host::BorderlessWindowChromeHitTarget::None:
    default:
        break;
    }

    InvalidateHostWindow();
}

} // namespace XCEngine::UI::Editor::App