PyQt5：QPainterが起動しない

QPainter()インスタンスが起動しません。

Pyrhon3
1def paint(self, point):
2  painter = QPainter()
3  painter.begin(self)
4




    
  painter.setPen(Qt.black)
5  painter.setBrush(QBrush(Qt.black), Qt.SolodPattern))
6  painter.drawEllipse(QPointF(point[0], point[1]), 5, 5)
以上のようなコードを実行したところ、以下のようなエラーが出ました。
QWidget::paintEngine: Should no longer be called
QPainter::begin: Paint device returned engine == 0, type: 1
QPainter::setPen: Painter not active
調べてみたところ、painter.begin()の引数として、QWidgetを渡すというような記述があり変更したところ、上記と同じエラーが出ました。

また、QPaintEventを使用する旨も見つけてはいるのですが、QPaintEventを使用した場合、上で書いたコードのように引数に点の座標を渡すことはできるのでしょうか？
上記のコードは、QPushButtonがクリックされた際に呼び出される点の値を計算する関数の中で呼び出されるものです。

QPaintEventを使用してもeventとして認識されませんでした。
ご教示いただけますと幸いです。よろしくお願いいたします。
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2 件の質問へのコメント
質問へのコメント
tiitoi
2018/11/14 04:35
QPainter を使って「何に」描画しようとしているのでしょうか？
Ykkykk
2018/11/14 04:39
QGraphicsSceneです。
<div class="questionCommentPost_agreeCheckBox__1_Jsc"><label class="checkbox_base__oWSFr checkbox_tiny__gu_qR"><input type="checkbox" checked="" class="checkbox_input__jEWYO"/><span><a href="/code-of-conduct" class="questionCommentPost_basicLink__glkTo" target="_blank" rel="noreferrer">行動規範</a>の内容に同意します</span></label></div><div class="questionCommentPost_footer__ZgDv6"><button type="button" class="button_base__e_zhG button_center__VP5Y6 button_royalblue__5QY6Z questionCommentPost_button__rHmbY" disabled="" data-testid="undefined-NeedLogin">コメントする</button></div></div></div></div></div></div><div class="question_questionAnswer__gy8Cn"><div class="flex_base__FcNvI flex_row__wMwQI flex_between__HuGAu questionAnswerArea_header__1_8Pg"><p class="txt_big__xTGYY txt_bold__gqe7O">回答<!-- -->1<!-- -->件</p><div class="dropdown_container__Ej7OM"><div class="collapse_container__N3I8v dropdown_collapse__42oKt"><button type="button" class="button_base__e_zhG dropdown_button__YMgz9">グッドが多い順</button></div></div></div><div id="reply-237149" class="answerBlock_container__LwiMm"><div class="answerBlock_inner__SrAEX"><div class="questionAnswerListItem_container__BM9Lp questionAnswerListItem_done__m27Zk"><div class="questionAnswerListItem_body__gshCC"><div class="questionAnswerListItem_sub__hW8hz"><p class="questionAnswerListItem_vote__BptVo" title="回答の評価">0</p></div><div class="questionAnswerListItem_main__osuvQ"><p class="questionAnswerListItem_label__gos1d"><img src="/img/icon/trophy_neocoral.svg" width="32" height="32" alt="" class="questionAnswerListItem_icon__767bU"/>ベストアンサー</p><div class="questionAnswerListItem_block__5ir6_"><div><div class="markdown-body markdown_markdownBody__SsVNy questionAnswerListItem_markdown__USv2Y"><p>QGraphcisScene に描画する場合、描画するオブジェクトを QGraphicsItem として作成する必要があります。</p>
<li>QGraphicsItem を継承したクラスを作成する。</li>
<li>paint(self, painter, option, widget) をオーバーライドする。</li>
<li>paint() 関数に渡ってくる painter オブジェクトで描画する。</li>
<h2 class="markdown_h2__nbka1">サンプルコード</h2>
<pre><div class="moreCollapse_container___Wuoc"><div><div class="markdown_codeWrapper__K4JAb"><p class="markdown_fileName__sVo7f">python</p><div node="[object Object]" style="color:black;background:transparent;text-shadow:0 1px white;font-family:Consolas, Monaco, 'Andale Mono', 'Ubuntu Mono', monospace;font-size:1em;text-align:left;white-space:pre;word-spacing:normal;word-break:normal;word-wrap:normal;line-height:1.5;-moz-tab-size:4;-o-tab-size:4;tab-size:4;-webkit-hyphens:none;-moz-hyphens:none;-ms-hyphens:none;hyphens:none;padding:0;margin:0;overflow:auto"><code class="language-python" style="color:black;background:none;text-shadow:0 1px white;font-family:Consolas, Monaco, 'Andale Mono', 'Ubuntu Mono', monospace;font-size:1em;text-align:left;white-space:pre;word-spacing:normal;word-break:normal;word-wrap:normal;line-height:1.5;-moz-tab-size:4;-o-tab-size:4;tab-size:4;-webkit-hyphens:none;-moz-hyphens:none;-ms-hyphens:none;hyphens:none"><span class="linenumber react-syntax-highlighter-line-number" style="display:inline-block;min-width:3.25em;padding-right:1em;text-align:right;user-select:none;color:slategray">1</span><span class="token" style="color:#07a">import</span><span> sys
<span class="linenumber react-syntax-highlighter-line-number" style="display:inline-block;min-width:3.25em;padding-right:1em;text-align:right;user-select:none;color:slategray">3</span><span/><span class="token" style="color:#07a">import</span><span> numpy </span><span class="token" style="color:#07a">as</span><span> np
</span><span class="linenumber react-syntax-highlighter-line-number" style="display:inline-block;min-width:3.25em;padding-right:1em;text-align:right;user-select:none;color:slategray">4</span><span/><span class="token" style="color:#07a">from</span><span> PyQt5</span><span class="token" style="color:#999">.</span><span>QtWidgets </span><span class="token" style="color:#07a">import</span><span> </span><span class="token" style="color:#9a6e3a;background:hsla(0, 0%, 100%, .5)">*</span><span>
</span><span class="linenumber react-syntax-highlighter-line-number" style="display:inline-block;min-width:3.25em;padding-right:1em;text-align:right;user-select:none;color:slategray">5</span><span/><span class="token" style="color:#07a">from</span><span> PyQt5</span><span class="token" style="color:#999">.</span><span>QtGui </span><span class="token" style="color:#07a">import</span><span> </span><span class="token" style="color:#9a6e3a;background:hsla(0, 0%, 100%, .5)">*</span><span>
</span><span class="linenumber react-syntax-highlighter-line-number" style="display:inline-block;min-width:3.25em;padding-right:1em;text-align:right;user-select:none;color:slategray">6</span><span/><span class="token" style="color:#07a">from</span><span> PyQt5</span><span class="token" style="color:#999">.</span><span>QtCore </span><span class="token" style="color:#07a">import</span><span> </span><span class="token" style="color:#9a6e3a;background:hsla(0, 0%, 100%, .5)">*</span><span>
<span class="linenumber react-syntax-highlighter-line-number" style="display:inline-block;min-width:3.25em;padding-right:1em;text-align:right;user-select:none;color:slategray">9</span><span/><span class="token" style="color:#07a">class</span><span> </span><span class="token" style="color:#DD4A68">StarGraphicsItem</span><span class="token" style="color:#999">(</span><span>QGraphicsItem</span><span class="token" style="color:#999">)</span><span class="token" style="color:#999">:</span><span>
</span><span class="linenumber react-syntax-highlighter-line-number" style="display:inline-block;min-width:3.25em;padding-right:1em;text-align:right;user-select:none;color:slategray">10</span><span>    </span><span class="token" style="color:#07a">def</span><span> </span><span class="token" style="color:#DD4A68">__init__</span><span class="token" style="color:#999">(</span><span>self</span><span class="token" style="color:#999">,</span><span> center</span><span class="token" style="color:#999">,</span><span> radius</span><span class="token" style="color:#999">,</span><span> parent</span><span class="token" style="color:#9a6e3a;background:hsla(0, 0%, 100%, .5)">=</span><span class="token" style="color:#905">None</span><span class="token" style="color:#999">)</span><span class="token" style="color:#999">:</span><span>
</span><span class="linenumber react-syntax-highlighter-line-number" style="display:inline-block;min-width:3.25em;padding-right:1em;text-align:right;user-select:none;color:slategray">11</span><span>        </span><span class="token" style="color:#690">super</span><span class="token" style="color:#999">(</span><span class="token" style="color:#999">)</span><span class="token" style="color:#999">.</span><span>__init__</span><span class="token" style="color:#999">(</span><span>parent</span><span class="token" style="color:#999">)</span><span>
</span><span class="linenumber react-syntax-highlighter-line-number" style="display:inline-block;min-width:3.25em;padding-right:1em;text-align:right;user-select:none;color:slategray">12</span><span>        self</span><span class="token" style="color:#999">.</span><span>center </span><span class="token" style="color:#9a6e3a;background:hsla(0, 0%, 100%, .5)">=</span><span> center
</span><span class="linenumber react-syntax-highlighter-line-number" style="display:inline-block;min-width:3.25em;padding-right:1em;text-align:right;user-select:none;color:slategray">13</span><span>        self</span><span class="token" style="color:#999">.</span><span>radius </span><span class="token" style="color:#9a6e3a;background:hsla(0, 0%, 100%, .5)">=</span><span> radius
<span class="linenumber react-syntax-highlighter-line-number" style="display:inline-block;min-width:3.25em;padding-right:1em;text-align:right;user-select:none;color:slategray">15</span><span>    </span><span class="token" style="color:#07a">def</span><span> </span><span class="token" style="color:#DD4A68">paint</span><span class="token" style="color:#999">(</span><span>self</span><span class="token" style="color:#999">,</span><span> painter</span><span class="token" style="color:#999">,</span><span> option</span><span class="token" style="color:#999">,</span><span> widget</span><span class="token" style="color:#999">)</span><span class="token" style="color:#999">:</span><span>
</span><span class="linenumber react-syntax-highlighter-line-number" style="display:inline-block;min-width:3.25em;padding-right:1em;text-align:right;user-select:none;color:slategray">16</span><span>        painter</span><span class="token" style="color:#999">.</span><span>setRenderHint</span><span class="token" style="color:#999">(</span><span>QPainter</span><span class="token" style="color:#999">.</span><span>Antialiasing</span><span class="token" style="color:#999">)</span><span>
</span><span class="linenumber react-syntax-highlighter-line-number" style="display:inline-block;min-width:3.25em;padding-right:1em;text-align:right;user-select:none;color:slategray">17</span><span>        </span><span class="token" style="color:slategray"># ペンとブラシを設定する。</span><span>
</span><span class="linenumber react-syntax-highlighter-line-number" style="display:inline-block;min-width:3.25em;padding-right:1em;text-align:right;user-select:none;color:slategray">18</span><span>        painter</span><span class="token" style="color:#999">.</span><span>setPen</span><span class="token" style="color:#999">(</span><span>QPen</span><span class="token" style="color:#999">(</span><span>Qt</span><span class="token" style="color:#999">.</span><span>black</span><span class="token" style="color:#999">,</span><span> </span><span class="token" style="color:#905">3</span><span class="token" style="color:#999">)</span><span class="token" style="color:#999">)</span><span>
</span><span class="linenumber react-syntax-highlighter-line-number" style="display:inline-block;min-width:3.25em;padding-right:1em;text-align:right;user-select:none;color:slategray">19</span><span>        painter</span><span class="token" style="color:#999">.</span><span>setBrush</span><span class="token" style="color:#999">(</span><span>Qt</span><span class="token" style="color:#999">.</span><span>yellow</span><span class="token" style="color:#999">)</span><span>
<span class="linenumber react-syntax-highlighter-line-number" style="display:inline-block;min-width:3.25em;padding-right:1em;text-align:right;user-select:none;color:slategray">21</span><span>        </span><span class="token" style="color:slategray"># ポリゴンを描画する。</span><span>
</span><span class="linenumber react-syntax-highlighter-line-number" style="display:inline-block;min-width:3.25em;padding-right:1em;text-align:right;user-select:none;color:slategray">22</span><span>        poly </span><span class="token" style="color:#9a6e3a;background:hsla(0, 0%, 100%, .5)">=</span><span> self</span><span class="token" style="color:#999">.</span><span>createShape</span><span class="token" style="color:#999">(</span><span class="token" style="color:#999">)</span><span>
</span><span class="linenumber react-syntax-highlighter-line-number" style="display:inline-block;min-width:3.25em;padding-right:1em;text-align:right;user-select:none;color:slategray">23</span><span>        painter</span><span class="token" style="color:#999">.</span><span>drawPolygon</span><span class="token" style="color:#999">(</span><span>poly</span><span class="token" style="color:#999">)</span><span>
<span class="linenumber react-syntax-highlighter-line-number" style="display:inline-block;min-width:3.25em;padding-right:1em;text-align:right;user-select:none;color:slategray">25</span><span>    </span><span class="token" style="color:#07a">def</span><span> </span><span class="token" style="color:#DD4A68">createShape</span><span class="token" style="color:#999">(</span><span>self</span><span class="token" style="color:#999">)</span><span class="token" style="color:#999">:</span><span>
</span><span class="linenumber react-syntax-highlighter-line-number" style="display:inline-block;min-width:3.25em;padding-right:1em;text-align:right;user-select:none;color:slategray">26</span><span>        </span><span class="token triple-quoted-string" style="color:#690">'''星を表すポリゴンを生成する。
</span><span class="linenumber react-syntax-highlighter-line-number" style="display:inline-block;min-width:3.25em;padding-right:1em;text-align:right;user-select:none;color:slategray">27</span><span class="token triple-quoted-string" style="color:#690">        '''</span><span>
</span><span class="linenumber react-syntax-highlighter-line-number" style="display:inline-block;min-width:3.25em;padding-right:1em;text-align:right;user-select:none;color:slategray">28</span><span>        </span><span class="token" style="color:slategray"># 点を生成する。</span><span>
</span><span class="linenumber react-syntax-highlighter-line-number" style="display:inline-block;min-width:3.25em;padding-right:1em;text-align:right;user-select:none;color:slategray">29</span><span>        num_points </span><span class="token" style="color:#9a6e3a;background:hsla(0, 0%, 100%, .5)">=</span><span> </span><span class="token" style="color:#905">11</span><span>
</span><span class="linenumber react-syntax-highlighter-line-number" style="display:inline-block;min-width:3.25em;padding-right:1em;text-align:right;user-select:none;color:slategray">30</span><span>        r </span><span class="token" style="color:#9a6e3a;background:hsla(0, 0%, 100%, .5)">=</span><span> self</span><span class="token" style="color:#999">.</span><span>radius </span><span class="token" style="color:#9a6e3a;background:hsla(0, 0%, 100%, .5)">*</span><span> np</span><span class="token" style="color:#999">.</span><span>where</span><span class="token" style="color:#999">(</span><span>np</span><span class="token" style="color:#999">.</span><span>arange</span><span class="token" style="color:#999">(</span><span>num_points</span><span class="token" style="color:#999">)</span><span> </span><span class="token" style="color:#9a6e3a;background:hsla(0, 0%, 100%, .5)">%</span><span> </span><span class="token" style="color:#905">2</span><span> </span><span class="token" style="color:#9a6e3a;background:hsla(0, 0%, 100%, .5)">==</span><span> </span><span class="token" style="color:#905">0</span><span class="token" style="color:#999">,</span><span> </span><span class="token" style="color:#905">0.5</span><span class="token" style="color:#999">,</span><span> </span><span class="token" style="color:#905">1</span><span class="token" style="color:#999">.</span><span class="token" style="color:#999">)</span><span>  </span><span class="token" style="color:slategray"># 半径</span><span>
</span><span class="linenumber react-syntax-highlighter-line-number" style="display:inline-block;min-width:3.25em;padding-right:1em;text-align:right;user-select:none;color:slategray">31</span><span>        theta </span><span class="token" style="color:#9a6e3a;background:hsla(0, 0%, 100%, .5)">=</span><span> np</span><span class="token" style="color:#999">.</span><span>linspace</span><span class="token" style="color:#999">(</span><span class="token" style="color:#905">0</span><span class="token" style="color:#999">,</span><span> </span><span class="token" style="color:#905">2</span><span> </span><span class="token" style="color:#9a6e3a;background:hsla(0, 0%, 100%, .5)">*</span><span> np</span><span class="token" style="color:#999">.</span><span>pi</span><span class="token" style="color:#999">,</span><span> num_points</span><span class="token" style="color:#999">)</span><span>  </span><span class="token" style="color:slategray"># 角度</span><span>
</span><span class="linenumber react-syntax-highlighter-line-number" style="display:inline-block;min-width:3.25em;padding-right:1em;text-align:right;user-select:none;color:slategray">32</span><span>        xs </span><span class="token" style="color:#9a6e3a;background:hsla(0, 0%, 100%, .5)">=</span><span> self</span><span class="token" style="color:#999">.</span><span>center</span><span class="token" style="color:#999">[</span><span class="token" style="color:#905">0</span><span class="token" style="color:#999">]</span><span> </span><span class="token" style="color:#9a6e3a;background:hsla(0, 0%, 100%, .5)">+</span><span> r </span><span class="token" style="color:#9a6e3a;background:hsla(0, 0%, 100%, .5)">*</span><span> np</span><span class="token" style="color:#999">.</span><span>sin</span><span class="token" style="color:#999">(</span><span>theta</span><span class="token" style="color:#999">)</span><span>  </span><span class="token" style="color:slategray"># x 座標</span><span>
</span><span class="linenumber react-syntax-highlighter-line-number" style="display:inline-block;min-width:3.25em;padding-right:1em;text-align:right;user-select:none;color:slategray">33</span><span>        ys </span><span class="token" style="color:#9a6e3a;background:hsla(0, 0%, 100%, .5)">=</span><span> self</span><span class="token" style="color:#999">.</span><span>center</span><span class="token" style="color:#999">[</span><span class="token" style="color:#905">1</span><span class="token" style="color:#999">]</span><span> </span><span class="token" style="color:#9a6e3a;background:hsla(0, 0%, 100%, .5)">+</span><span> r </span><span class="token" style="color:#9a6e3a;background:hsla(0, 0%, 100%, .5)">*</span><span> np</span><span class="token" style="color:#999">.</span><span>cos</span><span class="token" style="color:#999">(</span><span>theta</span><span class="token" style="color:#999">)</span><span>  </span><span class="token" style="color:slategray"># y 座標</span><span>
<span class="linenumber react-syntax-highlighter-line-number" style="display:inline-block;min-width:3.25em;padding-right:1em;text-align:right;user-select:none;color:slategray">35</span><span>        </span><span class="token" style="color:slategray"># QPolygonF に格納する。</span><span>
</span><span class="linenumber react-syntax-highlighter-line-number" style="display:inline-block;min-width:3.25em;padding-right:1em;text-align:right;user-select:none;color:slategray">36</span><span>        polygon </span><span class="token" style="color:#9a6e3a;background:hsla(0, 0%, 100%, .5)">=</span><span> QPolygonF</span><span class="token" style="color:#999">(</span><span class="token" style="color:#999">)</span><span>
</span><span class="linenumber react-syntax-highlighter-line-number" style="display:inline-block;min-width:3.25em;padding-right:1em;text-align:right;user-select:none;color:slategray">37</span><span>        </span><span class="token" style="color:#999">[</span><span>polygon</span><span class="token" style="color:#999">.</span><span>append</span><span class="token" style="color:#999">(</span><span>QPointF</span><span class="token" style="color:#999">(</span><span>x</span><span class="token" style="color:#999">,</span><span> y</span><span class="token" style="color:#999">)</span><span class="token" style="color:#999">)</span><span> </span><span class="token" style="color:#07a">for</span><span> x</span><span class="token" style="color:#999">,</span><span> y </span><span class="token" style="color:#07a">in</span><span> </span><span class="token" style="color:#690">zip</span><span class="token" style="color:#999">(</span><span>xs</span><span class="token" style="color:#999">,</span><span> ys</span><span class="token" style="color:#999">)</span><span class="token" style="color:#999">]</span><span>
<span class="linenumber react-syntax-highlighter-line-number" style="display:inline-block;min-width:3.25em;padding-right:1em;text-align:right;user-select:none;color:slategray">39</span><span>        </span><span class="token" style="color:#07a">return</span><span> polygon
<span class="linenumber react-syntax-highlighter-line-number" style="display:inline-block;min-width:3.25em;padding-right:1em;text-align:right;user-select:none;color:slategray">41</span><span>    </span><span class="token" style="color:#07a">def</span><span> </span><span class="token" style="color:#DD4A68">boundingRect</span><span class="token" style="color:#999">(</span><span>self</span><span class="token" style="color:#999">)</span><span class="token" style="color:#999">:</span><span>
</span><span class="linenumber react-syntax-highlighter-line-number" style="display:inline-block;min-width:3.25em;padding-right:1em;text-align:right;user-select:none;color:slategray">42</span><span>        </span><span class="token triple-quoted-string" style="color:#690">'''この図形を囲む矩形を返す。
</span><span class="linenumber react-syntax-highlighter-line-number" style="display:inline-block;min-width:3.25em;padding-right:1em;text-align:right;user-select:none;color:slategray">43</span><span class="token triple-quoted-string" style="color:#690">        '''</span><span>
<span class="linenumber react-syntax-highlighter-line-number" style="display:inline-block;min-width:3.25em;padding-right:1em;text-align:right;user-select:none;color:slategray">45</span><span>        </span><span class="token" style="color:#07a">return</span><span> QRectF</span><span class="token" style="color:#999">(</span><span>self</span><span class="token" style="color:#999">.</span><span>center</span><span class="token" style="color:#999">[</span><span class="token" style="color:#905">0</span><span class="token" style="color:#999">]</span><span> </span><span class="token" style="color:#9a6e3a;background:hsla(0, 0%, 100%, .5)">-</span><span> self</span><span class="token" style="color:#999">.</span><span>radius</span><span class="token" style="color:#999">,</span><span>
</span><span class="linenumber react-syntax-highlighter-line-number" style="display:inline-block;min-width:3.25em;padding-right:1em;text-align:right;user-select:none;color:slategray">46</span><span>                      self</span><span class="token" style="color:#999">.</span><span>center</span><span class="token" style="color:#999">[</span><span class="token" style="color:#905">1</span><span class="token" style="color:#999">]</span><span> </span><span class="token" style="color:#9a6e3a;background:hsla(0, 0%, 100%, .5)">-</span><span> self</span><span class="token" style="color:#999">.</span><span>radius</span><span class="token" style="color:#999">,</span><span>
</span><span class="linenumber react-syntax-highlighter-line-number" style="display:inline-block;min-width:3.25em;padding-right:1em;text-align:right;user-select:none;color:slategray">47</span><span>                      self</span><span class="token" style="color:#999">.</span><span>radius </span><span class="token" style="color:#9a6e3a;background:hsla(0, 0%, 100%, .5)">*</span><span> </span><span class="token" style="color:#905">2</span><span class="token" style="color:#999">,</span><span> self</span><span class="token" style="color:#999">.</span><span>radius </span><span class="token" style="color:#9a6e3a;background:hsla(0, 0%, 100%, .5)">*</span><span> </span><span class="token" style="color:#905">2</span><span class="token" style="color:#999">)</span><span>
<span class="linenumber react-syntax-highlighter-line-number" style="display:inline-block;min-width:3.25em;padding-right:1em;text-align:right;user-select:none;color:slategray">50</span><span/><span class="token" style="color:#07a">class</span><span> </span><span class="token" style="color:#DD4A68">MainWindow</span><span class="token" style="color:#999">(</span><span>QMainWindow</span><span class="token" style="color:#999">)</span><span class="token" style="color:#999">:</span><span>
</span><span class="linenumber react-syntax-highlighter-line-number" style="display:inline-block;min-width:3.25em;padding-right:1em;text-align:right;user-select:none;color:slategray">51</span><span>    </span><span class="token" style="color:#07a">def</span><span> </span><span class="token" style="color:#DD4A68">__init__</span><span class="token" style="color:#999">(</span><span>self</span><span class="token" style="color:#999">,</span><span> parent</span><span class="token" style="color:#9a6e3a;background:hsla(0, 0%, 100%, .5)">=</span><span class="token" style="color:#905">None</span><span class="token" style="color:#999">)</span><span class="token" style="color:#999">:</span><span>
</span><span class="linenumber react-syntax-highlighter-line-number" style="display:inline-block;min-width:3.25em;padding-right:1em;text-align:right;user-select:none;color:slategray">52</span><span>        </span><span class="token" style="color:#690">super</span><span class="token" style="color:#999">(</span><span class="token" style="color:#999">)</span><span class="token" style="color:#999">.</span><span>__init__</span><span class="token" style="color:#999">(</span><span>parent</span><span class="token" style="color:#999">)</span><span>
</span><span class="linenumber react-syntax-highlighter-line-number" style="display:inline-block;min-width:3.25em;padding-right:1em;text-align:right;user-select:none;color:slategray">53</span><span>        self</span><span class="token" style="color:#999">.</span><span>setGeometry</span><span class="token" style="color:#999">(</span><span class="token" style="color:#905">100</span><span class="token" style="color:#999">,</span><span> </span><span class="token" style="color:#905">100</span><span class="token" style="color:#999">,</span><span> </span><span class="token" style="color:#905">500</span><span class="token" style="color:#999">,</span><span> </span><span class="token" style="color:#905">500</span><span class="token" style="color:#999">)</span><span>
<span class="linenumber react-syntax-highlighter-line-number" style="display:inline-block;min-width:3.25em;padding-right:1em;text-align:right;user-select:none;color:slategray">55</span><span>        </span><span class="token" style="color:slategray"># シーンを作成する。</span><span>
</span><span class="linenumber react-syntax-highlighter-line-number" style="display:inline-block;min-width:3.25em;padding-right:1em;text-align:right;user-select:none;color:slategray">56</span><span>        starItem </span><span class="token" style="color:#9a6e3a;background:hsla(0, 0%, 100%, .5)">=</span><span> StarGraphicsItem</span><span class="token" style="color:#999">(</span><span>center</span><span class="token" style="color:#9a6e3a;background:hsla(0, 0%, 100%, .5)">=</span><span class="token" style="color:#999">(</span><span class="token" style="color:#905">100</span><span class="token" style="color:#999">,</span><span> </span><span class="token" style="color:#905">100</span><span class="token" style="color:#999">)</span><span class="token" style="color:#999">,</span><span> radius</span><span class="token" style="color:#9a6e3a;background:hsla(0, 0%, 100%, .5)">=</span><span class="token" style="color:#905">100</span><span class="token" style="color:#999">)</span><span>
</span><span class="linenumber react-syntax-highlighter-line-number" style="display:inline-block;min-width:3.25em;padding-right:1em;text-align:right;user-select:none;color:slategray">57</span><span>        self</span><span class="token" style="color:#999">.</span><span>scene </span><span class="token" style="color:#9a6e3a;background:hsla(0, 0%, 100%, .5)">=</span><span> QGraphicsScene</span><span class="token" style="color:#999">(</span><span class="token" style="color:#999">)</span><span>
</span><span class="linenumber react-syntax-highlighter-line-number" style="display:inline-block;min-width:3.25em;padding-right:1em;text-align:right;user-select:none;color:slategray">58</span><span>        self</span><span class="token" style="color:#999">.</span><span>scene</span><span class="token" style="color:#999">.</span><span>addItem</span><span class="token" style="color:#999">(</span><span>starItem</span><span class="token" style="color:#999">)</span><span>
<span class="linenumber react-syntax-highlighter-line-number" style="display:inline-block;min-width:3.25em;padding-right:1em;text-align:right;user-select:none;color:slategray">60</span><span>        </span><span class="token" style="color:slategray"># QGraphicsView</span><span>
</span><span class="linenumber react-syntax-highlighter-line-number" style="display:inline-block;min-width:3.25em;padding-right:1em;text-align:right;user-select:none;color:slategray">61</span><span>        graphicView </span><span class="token" style="color:#9a6e3a;background:hsla(0, 0%, 100%, .5)">=</span><span> QGraphicsView</span><span class="token" style="color:#999">(</span><span class="token" style="color:#999">)</span><span>
</span><span class="linenumber react-syntax-highlighter-line-number" style="display:inline-block;min-width:3.25em;padding-right:1em;text-align:right;user-select:none;color:slategray">62</span><span>        graphicView</span><span class="token" style="color:#999">.</span><span>setScene</span><span class="token" style="color:#999">(</span><span>self</span><span class="token" style="color:#999">.</span><span>scene</span><span class="token" style="color:#999">)</span><span>
<span class="linenumber react-syntax-highlighter-line-number" style="display:inline-block;min-width:3.25em;padding-right:1em;text-align:right;user-select:none;color:slategray">64</span><span>        </span><span class="token" style="color:slategray"># Central Widget</span><span>
</span><span class="linenumber react-syntax-highlighter-line-number" style="display:inline-block;min-width:3.25em;padding-right:1em;text-align:right;user-select:none;color:slategray">65</span><span>        central_widget </span><span class="token" style="color:#9a6e3a;background:hsla(0, 0%, 100%, .5)">=</span><span> QWidget</span><span class="token" style="color:#999">(</span><span class="token" style="color:#999">)</span><span>
</span><span class="linenumber react-syntax-highlighter-line-number" style="display:inline-block;min-width:3.25em;padding-right:1em;text-align:right;user-select:none;color:slategray">66</span><span>        self</span><span class="token" style="color:#999">.</span><span>setCentralWidget</span><span class="token" style="color:#999">(</span><span>central_widget</span><span class="token" style="color:#999">)</span><span>
<span class="linenumber react-syntax-highlighter-line-number" style="display:inline-block;min-width:3.25em;padding-right:1em;text-align:right;user-select:none;color:slategray">68</span><span>        </span><span class="token" style="color:slategray"># Layout</span><span>
</span><span class="linenumber react-syntax-highlighter-line-number" style="display:inline-block;min-width:3.25em;padding-right:1em;text-align:right;user-select:none;color:slategray">69</span><span>        layout </span><span class="token" style="color:#9a6e3a;background:hsla(0, 0%, 100%, .5)">=</span><span> QVBoxLayout</span><span class="token" style="color:#999">(</span><span class="token" style="color:#999">)</span><span>
</span><span class="linenumber react-syntax-highlighter-line-number" style="display:inline-block;min-width:3.25em;padding-right:1em;text-align:right;user-select:none;color:slategray">70</span><span>        layout</span><span class="token" style="color:#999">.</span><span>addWidget</span><span class="token" style="color:#999">(</span><span>graphicView</span><span class="token" style="color:#999">)</span><span>
</span><span class="linenumber react-syntax-highlighter-line-number" style="display:inline-block;min-width:3.25em;padding-right:1em;text-align:right;user-select:none;color:slategray">71</span><span>        central_widget</span><span class="token" style="color:#999">.</span><span>setLayout</span><span class="token" style="color:#999">(</span><span>layout</span><span class="token" style="color:#999">)</span><span>
<span class="linenumber react-syntax-highlighter-line-number" style="display:inline-block;min-width:3.25em;padding-right:1em;text-align:right;user-select:none;color:slategray">74</span><span/><span class="token" style="color:#07a">if</span><span> __name__ </span><span class="token" style="color:#9a6e3a;background:hsla(0, 0%, 100%, .5)">==</span><span> </span><span class="token" style="color:#690">'__main__'</span><span class="token" style="color:#999">:</span><span>
</span><span class="linenumber react-syntax-highlighter-line-number" style="display:inline-block;min-width:3.25em;padding-right:1em;text-align:right;user-select:none;color:slategray">75</span><span>    app </span><span class="token" style="color:#9a6e3a;background:hsla(0, 0%, 100%, .5)">=</span><span> QApplication</span><span class="token" style="color:#999">(</span><span>sys</span><span class="token" style="color:#999">.</span><span>argv</span><span class="token" style="color:#999">)</span><span>
</span><span class="linenumber react-syntax-highlighter-line-number" style="display:inline-block;min-width:3.25em;padding-right:1em;text-align:right;user-select:none;color:slategray">76</span><span>    main_window </span><span class="token" style="color:#9a6e3a;background:hsla(0, 0%, 100%, .5)">=</span><span> MainWindow</span><span class="token" style="color:#999">(</span><span class="token" style="color:#999">)</span><span>
<span class="linenumber react-syntax-highlighter-line-number" style="display:inline-block;min-width:3.25em;padding-right:1em;text-align:right;user-select:none;color:slategray">78</span><span>    main_window</span><span class="token" style="color:#999">.</span><span>show</span><span class="token" style="color:#999">(</span><span class="token" style="color:#999">)</span><span>
</span><span class="linenumber react-syntax-highlighter-line-number" style="display:inline-block;min-width:3.25em;padding-right:1em;text-align:right;user-select:none;color:slategray">79</span><span>    sys</span><span class="token" style="color:#999">.</span><span>exit</span><span class="token" style="color:#999">(</span><span>app</span><span class="token" style="color:#999">.</span><span>exec_</span><span class="token" style="color:#999">(</span><span class="token" style="color:#999">)</span><span class="token" style="color:#999">)</span><span>
<p><a href="https://teratail-v2.storage.googleapis.com/uploads/contributed_images/e2b85be32aabf2337a44b5d247f45d0d.png" target="_blank" rel="noreferrer"><img src="https://teratail-v2.storage.googleapis.com/uploads/contributed_images/e2b85be32aabf2337a44b5d247f45d0d.png" alt="イメージ説明" class="imageInMarkdown_img__0ADKi"/></a></p></div></div><div class="questionAnswerListItem_secondary__h7wgU"><div class="questionAnswerListItem_date__ScaW2"><p class="txt_mini__OBT1l">投稿<span class="questionAnswerListItem_datetimeText__mTHWN">2018/11/14 05:24</span></p></div><div class="userProfile_container__OwKvk"><div class="userProfile_inner__CjZGN"><div><div class="userProfile_stack1__AqVNr"><div class="userProfile_avatar__9CBg3"><a href="/users/tiitoi"><img src="https://teratail-v2.storage.googleapis.com/uploads/avatars/u9/99839/f4318c948acf0b76_thumbnail.png" alt="tiitoi" width="32" height="32" class="userThumnail_img__ggYRS"/></a></div><div class="userProfile_profile__wHNYH"><div 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class="answerCommentArea_isOpen__51iQK answerCommentArea_container__pLV_3"><div class="answerCommentArea_inner__lZ2ab answerCommentArea_nonTemplateButton__F_XfT"><div class="answerCommentArea_trigger__V4SQ5"><img src="/img/icon/review.svg" width="32" height="32" alt="" class="answerCommentArea_icon__sMyFZ"/><button type="button" class="button_base__e_zhG answerCommentArea_openButton__KU3mz"><span class="answerCommentArea_countText__TUV9f">5<!-- --> 件の</span>回答へのコメント</button></div><div class="answerCommentArea_target__3qwN2"><p class="answerCommentArea_header__Zpdln"><span class="answerCommentArea_icon__sMyFZ"><img src="/img/icon/review.svg" width="32" height="32" alt=""/></span><button type="button" class="button_base__e_zhG"><p class="txt_darkgray__CN95l txt_small__ivAjp answerCommentArea_title__foqxh">回答へのコメント</p></button></p><div class="answerCommentArea_answerCommentList__CSuT9"><div class=""><div class="partialListCollapse_collapse__q4r_o"><article class="answerCommentListItem_container___een_"><div class="answerCommentListItem_avatar__o3yx2"><a href="/users/Ykkykk"><img src="https://teratail-v2.storage.googleapis.com/uploads/avatars/u9/96891/RgTweK8f_thumbnail.jpg" alt="Ykkykk" width="32" height="32" class="userThumnail_img__ggYRS"/></a></div><div class="answerCommentListItem_content__sEL92"><div class="answerCommentListItem_meta__yzSKO"><img src="/img/icon/question_royalblue.svg" width="24" height="24" alt="" class="answerCommentListItem_icon__H7_EK"/><div class="answerCommentListItem_name__t8ebj"><div class="userName_userName__gBRt4"><a href="/users/Ykkykk" class="anchor_base__08kSU anchor_darkgray__X3Y2F anchor_large__7QBKp anchor_bold__A5M6p">Ykkykk</a></div></div><p class="txt_mini__OBT1l"><span>2018/11/14 06:14</span></p></div><div><div class="answerCommentListItem_comment__tHZht">ご回答いただきありがとうございます。詳細なコードまでご提示いただき大変勉強になります。
QGraphicsItemを使用せずに描画することはできないということですね。
本当にありがとうございます。</div></div></div></article><article class="answerCommentListItem_container___een_"><div class="answerCommentListItem_avatar__o3yx2"><a href="/users/tiitoi"><img src="https://teratail-v2.storage.googleapis.com/uploads/avatars/u9/99839/f4318c948acf0b76_thumbnail.png" alt="tiitoi" width="32" height="32" class="userThumnail_img__ggYRS"/></a></div><div class="answerCommentListItem_content__sEL92"><div class="answerCommentListItem_meta__yzSKO"><img src="/img/icon/answer_neocoral.svg" width="24" height="24" alt="" class="answerCommentListItem_icon__H7_EK"/><div class="answerCommentListItem_name__t8ebj"><div class="userName_userName__gBRt4"><a href="/users/tiitoi" class="anchor_base__08kSU anchor_darkgray__X3Y2F anchor_large__7QBKp anchor_bold__A5M6p">tiitoi</a></div></div><p class="txt_mini__OBT1l"><span>2018/11/14 06:20</span></p></div><div><div class="answerCommentListItem_comment__tHZht">線、画像、楕円、長方形、点、ポリゴンなど基本的な図形を表す QGraphicsItem はすでに用意されているので、複雑な図形もそれらを組み合わせれば描画できると思います。
例えば回答の例では、自分で QGraphicsItem を継承して作っていますが、ポリゴンの描画は QGraphicsPolygonItem を使っても同じことができます。</div></div></div></article><article class="answerCommentListItem_container___een_"><div class="answerCommentListItem_avatar__o3yx2"><a href="/users/Ykkykk"><img src="https://teratail-v2.storage.googleapis.com/uploads/avatars/u9/96891/RgTweK8f_thumbnail.jpg" alt="Ykkykk" width="32" height="32" class="userThumnail_img__ggYRS"/></a></div><div class="answerCommentListItem_content__sEL92"><div class="answerCommentListItem_meta__yzSKO"><img src="/img/icon/question_royalblue.svg" width="24" height="24" alt="" class="answerCommentListItem_icon__H7_EK"/><div class="answerCommentListItem_name__t8ebj"><div class="userName_userName__gBRt4"><a href="/users/Ykkykk" class="anchor_base__08kSU anchor_darkgray__X3Y2F anchor_large__7QBKp anchor_bold__A5M6p">Ykkykk</a></div></div><p class="txt_mini__OBT1l"><span>2018/11/14 06:27<!-- --> 編集</span></p></div><div><div class="answerCommentListItem_comment__tHZht">描画したいのは単純な円なのですが、addItemで一括して描画するのではなく、scene上に一つ一つ描画していきたいと思い、QGraphicsItemを使用しないで描画しようとしておりました。現在は、QGraphicsSceneのaddEllipseメソッドを使用しているのですが、アンチエイリアシングができずにガタガタになってしまうため、QPainterを使用できないのかと思っていた次第です。</div></div></div></article></div><button type="button" class="button_base__e_zhG button_block__8Lk6o button_center__VP5Y6 partialListCollapse_button__g8Oy3">過去3件のコメントを表示</button><article class="answerCommentListItem_container___een_"><div class="answerCommentListItem_avatar__o3yx2"><a href="/users/tiitoi"><img src="https://teratail-v2.storage.googleapis.com/uploads/avatars/u9/99839/f4318c948acf0b76_thumbnail.png" alt="tiitoi" width="32" height="32" class="userThumnail_img__ggYRS"/></a></div><div class="answerCommentListItem_content__sEL92"><div class="answerCommentListItem_meta__yzSKO"><img src="/img/icon/answer_neocoral.svg" width="24" height="24" alt="" class="answerCommentListItem_icon__H7_EK"/><div class="answerCommentListItem_name__t8ebj"><div class="userName_userName__gBRt4"><a href="/users/tiitoi" class="anchor_base__08kSU anchor_darkgray__X3Y2F anchor_large__7QBKp anchor_bold__A5M6p">tiitoi</a></div></div><p class="txt_mini__OBT1l"><span>2018/11/14 07:25<!-- --> 編集</span></p></div><div><div class="answerCommentListItem_comment__tHZht"><div><div class="morePanel_container__thG_D"><div class="morePanel_inner__fRYl7 answerCommentListItem_innerpanel__MhwJ7"><div>全アイテムにアンチエイリアス有効にしたいのであれば、QGraphicsView の setRenderHint() を設定すれよいです。
この設定は各アイテムで QPainter が描画する際に使用されます。
graphicView.setRenderHint(QPainter.Antialiasing)</div></div></div></div></div></div></div></article><article class="answerCommentListItem_container___een_"><div class="answerCommentListItem_avatar__o3yx2"><a href="/users/Ykkykk"><img src="https://teratail-v2.storage.googleapis.com/uploads/avatars/u9/96891/RgTweK8f_thumbnail.jpg" alt="Ykkykk" width="32" height="32" class="userThumnail_img__ggYRS"/></a></div><div class="answerCommentListItem_content__sEL92"><div class="answerCommentListItem_meta__yzSKO"><img src="/img/icon/question_royalblue.svg" width="24" height="24" alt="" class="answerCommentListItem_icon__H7_EK"/><div class="answerCommentListItem_name__t8ebj"><div class="userName_userName__gBRt4"><a href="/users/Ykkykk" class="anchor_base__08kSU anchor_darkgray__X3Y2F anchor_large__7QBKp anchor_bold__A5M6p">Ykkykk</a></div></div><p class="txt_mini__OBT1l"><span>2018/11/14 07:31</span></p></div><div><div class="answerCommentListItem_comment__tHZht"><div><div class="morePanel_container__thG_D"><div class="morePanel_inner__fRYl7 answerCommentListItem_innerpanel__MhwJ7"><div>加えてご回答くださり、ありがとうございます。
なるほど、QGraphicsViewにもsetRenderHintがあったのですね…。完全に見落としておりました。