CandidateWindow.cpp

//
//	Copyright (C) 2013 Hong Jen Yee (PCMan) <pcman.tw@gmail.com>
//
//	This library is free software; you can redistribute it and/or
//	modify it under the terms of the GNU Library General Public
//	License as published by the Free Software Foundation; either
//	version 2 of the License, or (at your option) any later version.
//
//	This library is distributed in the hope that it will be useful,
//	but WITHOUT ANY WARRANTY; without even the implied warranty of
//	MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
//	Library General Public License for more details.
//
//	You should have received a copy of the GNU Library General Public
//	License along with this library; if not, write to the
//	Free Software Foundation, Inc., 51 Franklin St, Fifth Floor,
//	Boston, MA  02110-1301, USA.
//

#include "CandidateWindow.h"
#include "DrawUtils.h"
#include "TextService.h"
#include "EditSession.h"

#include <tchar.h>
#include <windows.h>

using namespace std;

namespace Ime {

CandidateWindow::CandidateWindow(TextService* service, EditSession* session):
	ImeWindow(service),
	candPerRow_(1),
	textWidth_(0),
	itemHeight_(0),
	currentSel_(0),
	hasResult_(false),
	useCursor_(true),
	selKeyWidth_(0) {

	if(service->isImmersive()) { // windows 8 app mode
		margin_ = 10;
		rowSpacing_ = 8;
		colSpacing_ = 12;
	}
	else { // desktop mode
		margin_ = 5;
		rowSpacing_ = 4;
		colSpacing_ = 8;
	}

	HWND parent = service->compositionWindow(session);
	create(parent, WS_POPUP|WS_CLIPCHILDREN, WS_EX_TOOLWINDOW|WS_EX_TOPMOST);
}

CandidateWindow::~CandidateWindow(void) {
}

LRESULT CandidateWindow::wndProc(UINT msg, WPARAM wp , LPARAM lp) {
	switch (msg) {
		case WM_PAINT:
			onPaint(wp, lp);
			break;
		case WM_ERASEBKGND:
			return TRUE;
			break;
		case WM_LBUTTONDOWN:
			onLButtonDown(wp, lp);
			break;
		case WM_MOUSEMOVE:
			onMouseMove(wp, lp);
			break;
		case WM_LBUTTONUP:
			onLButtonUp(wp, lp);
			break;
		case WM_MOUSEACTIVATE:
			return MA_NOACTIVATE;
		default:
			return Window::wndProc(msg, wp, lp);
	}
	return 0;
}

void CandidateWindow::onPaint(WPARAM wp, LPARAM lp) {
	// TODO: check isImmersive_, and draw the window differently
	// in Windows 8 app immersive mode to follow windows 8 UX guidelines
	PAINTSTRUCT ps;
	BeginPaint(hwnd_, &ps);
	HDC hDC = ps.hdc;
	HFONT oldFont;
	RECT rc;

	oldFont = (HFONT)SelectObject(hDC, font_);

	GetClientRect(hwnd_,&rc);
	SetTextColor(hDC, GetSysColor(COLOR_WINDOWTEXT));
	SetBkColor(hDC, GetSysColor(COLOR_WINDOW));

	// paint window background and border
	// draw a flat black border in Windows 8 app immersive mode
	// draw a 3d border in desktop mode
	if(isImmersive()) {
		HPEN pen = ::CreatePen(PS_SOLID, 3, RGB(0, 0, 0));
		HGDIOBJ oldPen = ::SelectObject(hDC, pen);
		::Rectangle(hDC, rc.left, rc.top, rc.right, rc.bottom);
		::SelectObject(hDC, oldPen);
		::DeleteObject(pen);
	}
	else {
		// draw a 3d border in desktop mode
		::FillSolidRect(ps.hdc, rc.left, rc.top, rc.right - rc.left, rc.bottom - rc.top, GetSysColor(COLOR_WINDOW));
		::Draw3DBorder(hDC, &rc, GetSysColor(COLOR_3DFACE), 0);
	}

	// paint items
	int col = 0;
	int x = margin_, y = margin_;
	for(int i = 0, n = items_.size(); i < n; ++i) {
		paintItem(hDC, i, x, y);
		++col; // go to next column
		if(col >= candPerRow_) {
			col = 0;
			x = margin_;
			y += itemHeight_ + rowSpacing_;
		}
		else {
			x += colSpacing_ + selKeyWidth_ + textWidth_;
		}
	}
	SelectObject(hDC, oldFont);
	EndPaint(hwnd_, &ps);
}

void CandidateWindow::recalculateSize() {
	if(items_.empty()) {
		resize(margin_ * 2, margin_ * 2);
	}

	HDC hDC = ::GetWindowDC(hwnd());
	int height = 0;
	int width = 0;
	selKeyWidth_ = 0;
	textWidth_ = 0;
	itemHeight_ = 0;

	HGDIOBJ oldFont = ::SelectObject(hDC, font_);
	vector<wstring>::const_iterator it;
	for(int i = 0, n = items_.size(); i < n; ++i) {
		SIZE selKeySize;
		int lineHeight = 0;
		// the selection key string
		wchar_t selKey[] = L"?. ";
		selKey[0] = selKeys_[i];
		::GetTextExtentPoint32W(hDC, selKey, 3, &selKeySize);
		if(selKeySize.cx > selKeyWidth_)
			selKeyWidth_ = selKeySize.cx;

		// the candidate string
		SIZE candidateSize;
		wstring& item = items_.at(i);
		::GetTextExtentPoint32W(hDC, item.c_str(), item.length(), &candidateSize);
		if(candidateSize.cx > textWidth_)
			textWidth_ = candidateSize.cx;
		int itemHeight = max(candidateSize.cy, selKeySize.cy);
		if(itemHeight > itemHeight_)
			itemHeight_ = itemHeight;
	}
	::SelectObject(hDC, oldFont);
	::ReleaseDC(hwnd(), hDC);

	if(items_.size() <= candPerRow_) {
		width = items_.size() * (selKeyWidth_ + textWidth_);
		width += colSpacing_ * (items_.size() - 1);
		width += margin_ * 2;
		height = itemHeight_ + margin_ * 2;
	}
	else {
		width = candPerRow_ * (selKeyWidth_ + textWidth_);
		width += colSpacing_ * (candPerRow_ - 1);
		width += margin_ * 2;
		int rowCount = items_.size() / candPerRow_;
		if(items_.size() % candPerRow_)
			++rowCount;
		height = itemHeight_ * rowCount + rowSpacing_ * (rowCount - 1) + margin_ * 2;
	}
	resize(width, height);
}

void CandidateWindow::setCandPerRow(int n) {
	if(n != candPerRow_) {
		candPerRow_ = n;
		recalculateSize();
	}
}

bool CandidateWindow::filterKeyEvent(KeyEvent& keyEvent) {
	// select item with arrow keys
	int oldSel = currentSel_;
	switch(keyEvent.keyCode()) {
	case VK_UP:
		if(currentSel_ - candPerRow_ >=0)
			currentSel_ -= candPerRow_;
		break;
	case VK_DOWN:
		if(currentSel_ + candPerRow_ < items_.size())
			currentSel_ += candPerRow_;
		break;
	case VK_LEFT:
		if(currentSel_ - 1 >=0)
			--currentSel_;
		break;
	case VK_RIGHT:
		if(currentSel_ + 1 < items_.size())
			++currentSel_;
		break;
	case VK_RETURN:
		hasResult_ = true;
		return true;
	default:
		return false;
	}
	// if currently selected item is changed, redraw
	if(currentSel_ != oldSel) {
		// repaint the old and new items
		RECT rect;
		itemRect(oldSel, rect);
		::InvalidateRect(hwnd_, &rect, TRUE);
		itemRect(currentSel_, rect);
		::InvalidateRect(hwnd_, &rect, TRUE);
		return true;
	}
	return false;
}

void CandidateWindow::setCurrentSel(int sel) {
	if(sel >= items_.size())
		sel = 0;
	currentSel_ = sel;
	if(isVisible())
		::InvalidateRect(hwnd_, NULL, TRUE);
}

void CandidateWindow::clear() {
	items_.clear();
	selKeys_.clear();
	currentSel_ = 0;
	hasResult_ = false;
}

void CandidateWindow::setUseCursor(bool use) {
	useCursor_ = use;
	if(isVisible())
		::InvalidateRect(hwnd_, NULL, TRUE);
}

void CandidateWindow::paintItem(HDC hDC, int i,  int x, int y) {
	RECT textRect = {x, y, 0, y + itemHeight_};
	wchar_t selKey[] = L"?. ";
	selKey[0] = selKeys_[i];
	textRect.right = textRect.left + selKeyWidth_;
	// FIXME: make the color of strings configurable.
	COLORREF selKeyColor = RGB(0, 0, 255);
	COLORREF oldColor = ::SetTextColor(hDC, selKeyColor);
	// paint the selection key
	::ExtTextOut(hDC, textRect.left, textRect.top, ETO_OPAQUE, &textRect, selKey, 3, NULL);
	::SetTextColor(hDC, oldColor); // restore text color

	// paint the candidate string
	wstring& item = items_.at(i);
	textRect.left += selKeyWidth_;
	textRect.right = textRect.left + textWidth_;
	// paint the candidate string
	::ExtTextOut(hDC, textRect.left, textRect.top, ETO_OPAQUE, &textRect, item.c_str(), item.length(), NULL);

	if(useCursor_ && i == currentSel_) { // invert the selected item
		int left = textRect.left; // - selKeyWidth_;
		int top = textRect.top;
		int width = textRect.right - left;
		int height = itemHeight_;
		::BitBlt(hDC, left, top, width, itemHeight_, hDC, left, top, NOTSRCCOPY);
	}
}

void CandidateWindow::itemRect(int i, RECT& rect) {
	int row, col;
	row = i / candPerRow_;
	col = i % candPerRow_;
	rect.left = margin_ + col * (selKeyWidth_ + textWidth_ + colSpacing_);
	rect.top = margin_ + row * (itemHeight_ + rowSpacing_);
	rect.right = rect.left + (selKeyWidth_ + textWidth_);
	rect.bottom = rect.top + itemHeight_;
}


} // namespace Ime